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Splunk ESCU

2,101 vendor-native detections · ready to paste into your SIEM · cross-linked to ATT&CK

Detections

50 shown of 2,101
Splunk ESCU SPL T1127, T1685 ↗
ETW Registry Disabled
The following analytic detects a registry modification that disables the ETW for the .NET Framework. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the ETWEnabled registry value under the .NETFramework path. This activity is significant because disabling ETW can allow attackers to evade Endpoint Detection and Response (EDR) tools and hide their execution from audit logs. If confirmed malicious, this action could enable attackers to operate undetected, potentially leading to further compromise and persistent access within the environment.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*\\SOFTWARE\\Microsoft\\.NETFramework*" Registry.registry_value_name = ETWEnabled Registry.registry_value_data=0x00000000) by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `etw_registry_disabled_filter`
Splunk ESCU SPL T1069.002 ↗
Elevated Group Discovery With Wmic
The following analytic detects the execution of `wmic.exe` with command-line arguments querying specific elevated domain groups. It leverages Endpoint Detection and Response (EDR) telemetry to identify processes that access the LDAP namespace and search for groups like "Domain Admins" or "Enterprise Admins." This activity is significant as it indicates potential reconnaissance efforts by adversaries to identify high-privilege accounts within Active Directory. If confirmed malicious, this behavior could lead to privilege escalation, allowing attackers to gain elevated access and control over critical network resources.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.process_name="wmic.exe") (Processes.process=*/NAMESPACE:\\\\root\\directory\\ldap*) (Processes.process="*Domain Admins*" OR Processes.process="*Enterprise Admins*" OR Processes.process="*Schema Admins*" OR Processes.process="*Account Operators*" OR Processes.process="*Server Operators*" OR Processes.process="*Protected Users*" OR Processes.process="*Dns Admins*") by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `elevated_group_discovery_with_wmic_filter`
Splunk ESCU SPL T1069.002 ↗
Elevated Group Discovery with PowerView
The following analytic detects the execution of the `Get-DomainGroupMember` cmdlet from PowerView, identified through PowerShell Script Block Logging (EventCode=4104). This cmdlet is used to enumerate members of elevated domain groups such as Domain Admins and Enterprise Admins. Monitoring this activity is crucial as it indicates potential reconnaissance efforts by adversaries to identify high-privileged users within the domain. If confirmed malicious, this activity could lead to targeted attacks on privileged accounts, facilitating further compromise and lateral movement within the network.
Show query
`powershell` EventCode=4104 (ScriptBlockText = "*Get-DomainGroupMember*") AND ScriptBlockText IN ("*Domain Admins*","*Enterprise Admins*", "*Schema Admins*", "*Account Operators*" , "*Server Operators*", "*Protected Users*",  "*Dns Admins*")
  | fillnull
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product EventID
       Guid Opcode Name
       Path ProcessID ScriptBlockId
       ScriptBlockText
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `elevated_group_discovery_with_powerview_filter`
Splunk ESCU SPL T1566.001, T1036.008 ↗
Email Attachments With Lots Of Spaces
The following analytic detects email attachments with an unusually high number of spaces in their file names, which is a common tactic used by attackers to obfuscate file extensions. It leverages the Email data model to identify attachments where the ratio of spaces to the total file name length exceeds 10%. This behavior is significant as it may indicate an attempt to bypass security filters and deliver malicious payloads. If confirmed malicious, this activity could lead to the execution of harmful code or unauthorized access to sensitive information within the recipient's environment.
Show query
| tstats `security_content_summariesonly` count values(All_Email.recipient) as recipient_address min(_time) as firstTime max(_time) as lastTime FROM datamodel=Email
  WHERE All_Email.file_name="*"
  BY All_Email.src_user, All_Email.file_name All_Email.message_id
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `drop_dm_object_name("All_Email")`
| eval space_ratio = (mvcount(split(file_name," "))-1)/len(file_name)
| search space_ratio >= 0.1
| rex field=recipient_address "(?<recipient_user>.*)@"
| `email_attachments_with_lots_of_spaces_filter`
Splunk ESCU SPL T1114.001 ↗
Email files written outside of the Outlook directory
The following analytic detects email files (.pst or .ost) being created outside the standard Outlook directories. It leverages the Endpoint.Filesystem data model to identify file creation events and filters for email files not located in "C:\Users\*\My Documents\Outlook Files\*" or "C:\Users\*\AppData\Local\Microsoft\Outlook*". This activity is significant as it may indicate data exfiltration or unauthorized access to email data. If confirmed malicious, an attacker could potentially access sensitive email content, leading to data breaches or further exploitation within the network.
Show query
| tstats `security_content_summariesonly` count values(Filesystem.file_path) as file_path min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem
  WHERE (
        Filesystem.file_name=*.pst
        OR
        Filesystem.file_name=*.ost
    )
    Filesystem.file_path != "C:\Users\*\My Documents\Outlook Files\*"  Filesystem.file_path!="C:\Users\*\AppData\Local\Microsoft\Outlook*"
  BY Filesystem.action Filesystem.dest Filesystem.file_access_time
     Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time
     Filesystem.file_name Filesystem.file_path Filesystem.file_acl
     Filesystem.file_size Filesystem.process_guid Filesystem.process_id
     Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name("Filesystem")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `email_files_written_outside_of_the_outlook_directory_filter`
Splunk ESCU SPL T1114.002 ↗
Email servers sending high volume traffic to hosts
The following analytic identifies a significant increase in data transfers from your email server to client hosts. It leverages the Network_Traffic data model to monitor outbound traffic from email servers, using statistical analysis to detect anomalies based on average and standard deviation metrics. This activity is significant as it may indicate a malicious actor exfiltrating data via your email server. If confirmed malicious, this could lead to unauthorized data access and potential data breaches, compromising sensitive information and impacting organizational security.
Show query
| tstats `security_content_summariesonly` sum(All_Traffic.bytes_out) as bytes_out FROM datamodel=Network_Traffic
  WHERE All_Traffic.src_category=email_server
  BY All_Traffic.dest_ip _time span=1d
| `drop_dm_object_name("All_Traffic")`
| eventstats avg(bytes_out) as avg_bytes_out stdev(bytes_out) as stdev_bytes_out
| eventstats count as num_data_samples avg(eval(if(_time < relative_time(now(), "@d"), bytes_out, null))) as per_source_avg_bytes_out stdev(eval(if(_time < relative_time(now(), "@d"), bytes_out, null))) as per_source_stdev_bytes_out
  BY dest_ip
| eval minimum_data_samples = 4, deviation_threshold = 3
| where num_data_samples >= minimum_data_samples AND bytes_out > (avg_bytes_out + (deviation_threshold * stdev_bytes_out)) AND bytes_out > (per_source_avg_bytes_out + (deviation_threshold * per_source_stdev_bytes_out)) AND _time >= relative_time(now(), "@d")
| eval num_standard_deviations_away_from_server_average = round(abs(bytes_out - avg_bytes_out) / stdev_bytes_out, 2), num_standard_deviations_away_from_client_average = round(abs(bytes_out - per_source_avg_bytes_out) / per_source_stdev_bytes_out, 2)
| table dest_ip, _time, bytes_out, avg_bytes_out, per_source_avg_bytes_out, num_standard_deviations_away_from_server_average, num_standard_deviations_away_from_client_average
| `email_servers_sending_high_volume_traffic_to_hosts_filter`
Splunk ESCU SPL T1021 ↗
Enable RDP In Other Port Number
The following analytic detects modifications to the registry that enable RDP on a machine using a non-default port number. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the registry path "HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" and the "PortNumber" value. This activity is significant as attackers often modify RDP settings to facilitate lateral movement and maintain remote access to compromised systems. If confirmed malicious, this could allow attackers to bypass network defenses, gain persistent access, and potentially control the compromised machine.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*\\CurrentControlSet\\Control\\Terminal Server\\WinStations\\RDP-Tcp*" Registry.registry_value_name = "PortNumber") by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `enable_rdp_in_other_port_number_filter`
Splunk ESCU SPL T1112, T1003 ↗
Enable WDigest UseLogonCredential Registry
The following analytic detects a suspicious registry modification that enables the plain text credential feature in Windows by setting the "UseLogonCredential" value to 1 in the WDigest registry path. This detection leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values. This activity is significant because it is commonly used by malware and tools like Mimikatz to dump plain text credentials, indicating a potential credential dumping attempt. If confirmed malicious, this could allow an attacker to obtain sensitive credentials, leading to further compromise and lateral movement within the network.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*\\System\\CurrentControlSet\\Control\\SecurityProviders\\WDigest\\*" Registry.registry_value_name = "UseLogonCredential" Registry.registry_value_data=0x00000001) by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `enable_wdigest_uselogoncredential_registry_filter`
Splunk ESCU SPL T1087 ↗
Enumerate Users Local Group Using Telegram
The following analytic detects a Telegram process enumerating all network users in a local group. It leverages EventCode 4798, which is generated when a process enumerates a user's security-enabled local groups on a computer or device. This activity is significant as it may indicate an attempt to gather information on user accounts, a common precursor to further malicious actions. If confirmed malicious, this behavior could allow an attacker to map out user accounts, potentially leading to privilege escalation or lateral movement within the network.
Show query
`wineventlog_security` EventCode=4798  CallerProcessName = "*\\telegram.exe" | stats count min(_time) as firstTime max(_time) as lastTime by user Computer EventCode CallerProcessName  ProcessID SubjectUserSid SubjectDomainName  SubjectLogonId | rename Computer as dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `enumerate_users_local_group_using_telegram_filter`
Splunk ESCU SPL T1003.002 ↗
Esentutl SAM Copy
The following analytic detects the use of `esentutl.exe` to access credentials stored in the ntds.dit or SAM file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because it may indicate an attempt to extract sensitive credential information, which is a common tactic in lateral movement and privilege escalation. If confirmed malicious, this could allow an attacker to gain unauthorized access to user credentials, potentially compromising the entire network.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime from datamodel=Endpoint.Processes where
(Processes.process_name=esentutl.exe OR Processes.original_file_name=esentutl.exe)
Processes.process IN ("*ntds*", "*SAM*")
by Processes.action Processes.dest Processes.original_file_name
   Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
   Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
   Processes.process Processes.process_exec Processes.process_guid Processes.process_hash
   Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path
   Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `esentutl_sam_copy_filter`
Splunk ESCU SPL T1548.002 ↗
Eventvwr UAC Bypass
The following analytic detects an Eventvwr UAC bypass by identifying suspicious registry modifications in the path that Eventvwr.msc references upon execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry changes and process execution details. This activity is significant because it indicates a potential privilege escalation attempt, allowing an attacker to execute arbitrary commands with elevated privileges. If confirmed malicious, this could lead to unauthorized code execution, persistence, and further compromise of the affected system.
Show query
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path="*mscfile\\shell\\open\\command\\*") by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `eventvwr_uac_bypass_filter`
Splunk ESCU SPL T1489 ↗
Excessive Attempt To Disable Services
The following analytic identifies a suspicious series of command-line executions attempting to disable multiple services. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes where "sc.exe" is used with parameters like "config" or "Disabled" within a short time frame. This activity is significant as it may indicate an adversary's attempt to disable security or other critical services to further compromise the system. If confirmed malicious, this could lead to the attacker achieving persistence, evading detection, or disabling security mechanisms, thereby increasing the risk of further exploitation.
Show query
| tstats `security_content_summariesonly` values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process) as parent_process values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product  count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "sc.exe"
    AND
    Processes.process="*config*"
    OR
    Processes.process="*Disabled*"
  BY Processes.process_name Processes.parent_process_name Processes.dest
     Processes.user _time span=1m
| where count >=4
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_attempt_to_disable_services_filter`
Splunk ESCU SPL T1071.004 ↗
Excessive DNS Failures
The following analytic identifies excessive DNS query failures by counting DNS responses that do not indicate success, triggering when there are more than 50 occurrences. It leverages the Network_Resolution data model, focusing on DNS reply codes that signify errors. This activity is significant because a high number of DNS failures can indicate potential network misconfigurations, DNS poisoning attempts, or malware communication issues. If confirmed malicious, this activity could lead to disrupted network services, hindered communication, or data exfiltration attempts by attackers.
Show query
| tstats `security_content_summariesonly` count FROM datamodel=Network_Resolution
  WHERE nodename=DNS "DNS.reply_code"!="No Error" "DNS.reply_code"!="NoError" DNS.reply_code!="unknown" NOT "DNS.query"="*.arpa" "DNS.query"="*.*"
  BY "DNS.src" "DNS.query" "DNS.reply_code"
| `drop_dm_object_name("DNS")`
| lookup cim_corporate_web_domain_lookup domain as query OUTPUT domain
| where isnull(domain)
| lookup update=true alexa_lookup_by_str domain as query OUTPUT rank
| where isnull(rank)
| eventstats max(count) as mc
  BY src reply_code
| eval mode_query=if(count=mc, query, null())
| stats sum(count) as count values(mode_query) as query values(mc) as max_query_count
  BY src reply_code
| where count>50
| `get_asset(src)`
| `excessive_dns_failures_filter`
Splunk ESCU SPL T1485 ↗
Excessive File Deletion In WinDefender Folder
The following analytic detects excessive file deletion events in the Windows Defender folder. It leverages Sysmon EventCodes 23 and 26 to identify processes deleting multiple files within this directory. This behavior is significant as it may indicate an attempt to corrupt or disable Windows Defender, a key security component. If confirmed malicious, this activity could allow an attacker to disable endpoint protection, facilitating further malicious actions without detection.
Show query
`sysmon` EventCode IN ("23","26") TargetFilename = "*\\ProgramData\\Microsoft\\Windows Defender\\*" | stats count min(_time) as firstTime, max(_time) as lastTime values(file_path) as file_path values(file_hash) as file_hash values(file_name) as file_name values(file_modify_time) as file_modify_time values(process_name) as process_name values(process_path) as process_path values(process_guid) as process_guid values(process_id) as process_id values(process_exec) as process_exec by action dest dvc signature signature_id user user_id vendor_product | where count >=50 | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `excessive_file_deletion_in_windefender_folder_filter`
Splunk ESCU SPL T1222 ↗
Excessive Usage Of Cacls App
The following analytic identifies excessive usage of `cacls.exe`, `xcacls.exe`, or `icacls.exe` to change file or folder permissions. It looks for 10 or more execution of the aforementioned processes in the span of 1 minute. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it may indicate an adversary attempting to restrict access to malware components or artifacts on a compromised system. If confirmed malicious, this behavior could prevent users from deleting or accessing critical files, aiding in the persistence and concealment of malicious activities.
Show query
| tstats `security_content_summariesonly`
  min(_time) as firstTime
  max(_time) as lastTime
  values(Processes.dest) as dest
  values(Processes.user) as user
  values(Processes.action) as action
  values(Processes.original_file_name) as original_file_name
  values(Processes.parent_process_exec) as parent_process_exec
  values(Processes.parent_process_guid) as parent_process_guid
  values(Processes.parent_process_id) as parent_process_id
  values(Processes.parent_process_path) as parent_process_path
  values(Processes.process) as process
  values(Processes.process_exec) as process_exec
  values(Processes.process_guid) as process_guid
  values(Processes.process_hash) as process_hash
  values(Processes.process_id) as process_id
  values(Processes.process_integrity_level) as process_integrity_level
  values(Processes.process_name) as process_name
  values(Processes.process_path) as process_path
  values(Processes.user_id) as user_id
  values(Processes.vendor_product) as vendor_product count
from datamodel=Endpoint.Processes where
Processes.process_name IN( "icacls.exe", "cacls.exe", "xcacls.exe")
by Processes.parent_process_name Processes.parent_process Processes.dest Processes.user _time span=1m
| where count >=10
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_usage_of_cacls_app_filter`
Splunk ESCU SPL T1569.002 ↗
Excessive Usage Of SC Service Utility
The following analytic detects excessive usage of the `sc.exe` service utility on a host machine. It leverages Sysmon EventCode 1 logs to identify instances where `sc.exe` is executed more frequently than normal within a 15-minute window. This behavior is significant as it is commonly associated with ransomware, cryptocurrency miners, and other malware attempting to create, modify, delete, or disable services, potentially related to security applications or for privilege escalation. If confirmed malicious, this activity could allow attackers to manipulate critical services, leading to system compromise or disruption of security defenses.
Show query
| tstats `security_content_summariesonly` count as numScExe min(_time) as firstTime max(_time) as lastTime values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product values(Processes.parent_process) as parent_process values(Processes.process_name) as process_name values(Processes.parent_process_id) as parent_process_id values(Processes.user) as user FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "sc.exe"
  BY Processes.dest _time span=15m
| `drop_dm_object_name(Processes)`
| eventstats avg(numScExe) as avgScExe, stdev(numScExe) as stdScExe, count as numSlots
  BY dest
| eval upperThreshold=(avgScExe + stdScExe *3)
| eval isOutlier=if(avgScExe > 5 and avgScExe >= upperThreshold, 1, 0)
| search isOutlier=1
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_usage_of_sc_service_utility_filter`
Splunk ESCU SPL T1685 ↗
Excessive Usage Of Taskkill
The following analytic identifies excessive usage of `taskkill.exe`, a command-line utility used to terminate processes. The detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on instances where `taskkill.exe` is executed ten or more times within a one-minute span. This behavior is significant as adversaries often use `taskkill.exe` to disable security tools or other critical processes to evade detection. If confirmed malicious, this activity could allow attackers to bypass security defenses, maintain persistence, and further compromise the system.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Processes.action) as action values(Processes.dest) as dest values(Processes.original_file_name) as original_file_name values(Processes.parent_process) as parent_process values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user) as user  values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "taskkill.exe"
  BY Processes.parent_process_name Processes.process_name Processes.dest
     Processes.user _time span=1m
| where count >=10
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_usage_of_taskkill_filter`
Splunk ESCU SPL T1048 ↗
Excessive Usage of NSLOOKUP App
The following analytic detects excessive usage of the nslookup application, which may indicate potential DNS exfiltration attempts. It leverages Sysmon EventCode 1 to monitor process executions, specifically focusing on nslookup.exe. The detection identifies outliers by comparing the frequency of nslookup executions against a calculated threshold. This activity is significant as it can reveal attempts by malware or APT groups to exfiltrate data via DNS queries. If confirmed malicious, this behavior could allow attackers to stealthily transfer sensitive information out of the network, bypassing traditional data exfiltration defenses.
Show query
| tstats `security_content_summariesonly` count as numNsLookup min(_time) as firstTime max(_time) as lastTime values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product values(Processes.parent_process) as parent_process values(Processes.process_name) as process_name values(Processes.parent_process_id) as parent_process_id values(Processes.user) as user FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "nslookup.exe"
  BY Processes.dest _time span=1m
| `drop_dm_object_name(Processes)`
| eventstats avg(numNsLookup) as avgNsLookup, stdev(numNsLookup) as stdNsLookup, count as numSlots
  BY dest
| eval upperThreshold=(avgNsLookup + stdNsLookup *3)
| eval isOutlier=if(numNsLookup > 20 and numNsLookup >= upperThreshold, 1, 0)
| search isOutlier=1
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_usage_of_nslookup_app_filter`
Splunk ESCU SPL T1059 ↗
Excessive distinct processes from Windows Temp
The following analytic identifies an excessive number of distinct processes executing from the Windows\Temp directory. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process paths and counts within a 20-minute window. This behavior is significant as it often indicates the presence of post-exploit frameworks like Koadic and Meterpreter, which use this technique to execute malicious actions. If confirmed malicious, this activity could allow attackers to execute arbitrary code, escalate privileges, and maintain persistence within the environment, posing a severe threat to system integrity and security.
Show query
| tstats `security_content_summariesonly` distinct_count(Processes.process) as distinct_process_count min(_time) as firstTime max(_time) as lastTime values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process) as parent_process values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_name) as process_name values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product from datamodel=Endpoint.Processes where Processes.process_path = "*\\Windows\\Temp\\*" by Processes.dest Processes.user _time span=20m |  where distinct_process_count > 37 | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `excessive_distinct_processes_from_windows_temp_filter`
Splunk ESCU SPL T1685 ↗
Excessive number of service control start as disabled
The following analytic detects an excessive number of `sc.exe` processes launched with the command line argument `start= disabled` within a short period. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, command-line executions, and process GUIDs. This activity is significant as it may indicate an attempt to disable critical services, potentially impairing system defenses. If confirmed malicious, this behavior could allow an attacker to disrupt security mechanisms, hinder incident response, and maintain control over the compromised system.
Show query
| tstats `security_content_summariesonly` distinct_count(Processes.process) as distinct_cmdlines values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "sc.exe"
    AND
    Processes.process="*start= disabled*"
  BY Processes.dest Processes.user Processes.parent_process
     Processes.process_name Processes.parent_process_id, _time
     span=30m
| where distinct_cmdlines >= 8
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_number_of_service_control_start_as_disabled_filter`
Splunk ESCU SPL T1059 ↗
Excessive number of taskhost processes
The following analytic identifies an excessive number of taskhost.exe and taskhostex.exe processes running within a short time frame. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and their counts. This behavior is significant as it is commonly associated with post-exploitation tools like Meterpreter and Koadic, which use multiple instances of these processes for actions such as discovery and lateral movement. If confirmed malicious, this activity could indicate an ongoing attack, allowing attackers to execute code, escalate privileges, or move laterally within the network.
Show query
| tstats `security_content_summariesonly` values(Processes.action) as action values(Processes.original_file_name) as original_file_name values(Processes.parent_process) as parent_process values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_id) as process_id values(Processes.process_integrity_level) as process_integrity_level values(Processes.user) as user values(Processes.process_path) as process_path values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "taskhost.exe"
    OR
    Processes.process_name = "taskhostex.exe"
  BY Processes.dest Processes.process_name _time
     span=1h
| `drop_dm_object_name(Processes)`
| eval pid_count=mvcount(process_id)
| eval taskhost_count_=if(process_name == "taskhost.exe", pid_count, 0)
| eval taskhostex_count_=if(process_name == "taskhostex.exe", pid_count, 0)
| stats sum(taskhost_count_) as taskhost_count, sum(taskhostex_count_) as taskhostex_count values(action) as action values(original_file_name) as original_file_name values(parent_process) as parent_process values(parent_process_exec) as parent_process_exec values(parent_process_guid) as parent_process_guid values(parent_process_id) as parent_process_id values(parent_process_name) as parent_process_name values(parent_process_path) as parent_process_path values(process) as process values(process_exec) as process_exec values(process_guid) as process_guid values(process_hash) as process_hash values(process_id) as process_id values(process_integrity_level) as process_integrity_level values(user) as user values(process_path) as process_path values(user_id) as user_id values(vendor_product) as vendor_product values(process_name) as process_name
  BY _time, dest, firstTime,
     lastTime
| where taskhost_count > 10 or taskhostex_count > 10
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `excessive_number_of_taskhost_processes_filter`
Splunk ESCU SPL T1190, T1133 ↗
Exchange PowerShell Abuse via SSRF
The following analytic detects suspicious behavior indicative of ProxyShell exploitation against on-premise Microsoft Exchange servers. It identifies HTTP POST requests to `autodiscover.json` containing `PowerShell` in the URI, leveraging server-side request forgery (SSRF) to access backend PowerShell. This detection uses Exchange server logs ingested into Splunk. Monitoring this activity is crucial as it may indicate an attacker attempting to execute commands or scripts on the Exchange server. If confirmed malicious, this could lead to unauthorized access, privilege escalation, or persistent control over the Exchange environment.
Show query
`windows_exchange_iis` c_uri="*//autodiscover*" cs_uri_query="*PowerShell*" cs_method="POST"
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY dest, cs_uri_query, cs_method,
       c_uri
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `exchange_powershell_abuse_via_ssrf_filter`
Splunk ESCU SPL T1059.001 ↗
Exchange PowerShell Module Usage
The following analytic detects the usage of specific Exchange PowerShell modules, such as New-MailboxExportRequest, New-ManagementRoleAssignment, New-MailboxSearch, and Get-Recipient. It leverages PowerShell Script Block Logging (EventCode 4104) to identify these commands. This activity is significant because these modules can be exploited by adversaries who have gained access via ProxyShell or ProxyNotShell vulnerabilities. If confirmed malicious, attackers could export mailbox contents, assign management roles, conduct mailbox searches, or view recipient objects, potentially leading to data exfiltration, privilege escalation, or unauthorized access to sensitive information.
Show query
`powershell` EventCode=4104 ScriptBlockText IN ("*New-MailboxExportRequest*", "*New-ManagementRoleAssignment*", "*New-MailboxSearch*", "*Get-Recipient*", "Search-Mailbox")
  | fillnull
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY dest signature signature_id
       user_id vendor_product EventID
       Guid Opcode Name
       Path ProcessID ScriptBlockId
       ScriptBlockText
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `exchange_powershell_module_usage_filter`
Splunk ESCU SPL T1021.002 ↗
Executable File Written in Administrative SMB Share
The following analytic detects executable files (.exe or .dll) being written to Windows administrative SMB shares (Admin$, IPC$, C$). It leverages Windows Security Event Logs with EventCode 5145 to identify this activity. This behavior is significant as it is commonly used by tools like PsExec/PaExec for staging binaries before creating and starting services on remote endpoints, a technique often employed for lateral movement and remote code execution. If confirmed malicious, this activity could allow an attacker to execute arbitrary code remotely, potentially compromising additional systems within the network.
Show query
`wineventlog_security` EventCode=5145 RelativeTargetName IN ("*.exe","*.dll") ObjectType=File ShareName IN ("\\\\*\\C$","\\\\*\\IPC$","\\\\*\\admin$") AccessMask= "0x2" | stats min(_time) as firstTime max(_time) as lastTime count by EventCode ShareName RelativeTargetName ObjectType AccessMask src_user src_port IpAddress dest | `security_content_ctime(firstTime)`  | `executable_file_written_in_administrative_smb_share_filter`
Splunk ESCU SPL T1036 ↗
Executables Or Script Creation In Suspicious Path
The following analytic identifies the creation of executables or scripts in suspicious file paths on Windows systems. It leverages the Endpoint.Filesystem dataset to detect files with specific extensions (e.g., .exe, .dll, .ps1) created in uncommon directories (e.g., \windows\fonts\, \users\public\). This activity can be significant as adversaries often use these paths to evade detection and maintain persistence. If confirmed malicious, this behavior could allow attackers to execute unauthorized code, escalate privileges, or persist within the environment, posing a significant security threat.
Show query
| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime
from datamodel=Endpoint.Filesystem where
Filesystem.file_name IN (
    "*.bat",
    "*.cmd",
    "*.com",
    "*.dll",
    "*.exe",
    "*.js",
    "*.msc",
    "*.pif",
    "*.ps1",
    "*.sys",
    "*.vbe",
    "*.vbs"
)
Filesystem.file_path IN (
    "*:\\PerfLogs\\*",
    "*:\\Users\\Administrator\\Music\\*",
    "*:\\Users\\Default\\*",
    "*:\\Users\\Public\\*",
    "*:\\Windows\\debug\\*",
    "*:\\Windows\\fonts\\*",
    "*:\\Windows\\Media\\*",
    "*:\\Windows\\repair\\*",
    "*:\\Windows\\servicing\\*",
    "*\\inetpub\\*",
    "*\\Microsoft\\Windows\\Libraries\\*",
    "*Recycle.bin*"
)
by Filesystem.action Filesystem.dest Filesystem.file_access_time
   Filesystem.file_create_time Filesystem.file_hash
   Filesystem.file_modify_time Filesystem.file_name
   Filesystem.file_path Filesystem.file_acl Filesystem.file_size
   Filesystem.process_guid Filesystem.process_id Filesystem.user
   Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `executables_or_script_creation_in_suspicious_path_filter`
Splunk ESCU SPL T1036 ↗
Executables Or Script Creation In Temp Path
The following analytic identifies the creation of executables or scripts in temporary file paths on Windows systems. It leverages the Endpoint.Filesystem data set to detect files with specific extensions (e.g., .exe, .dll, .ps1) created in temporary directories (e.g., \windows\Temp\, \AppData\Local\Temp\). This activity can be significant as adversaries often use these paths to evade detection and maintain persistence. If confirmed malicious, this behavior could allow attackers to execute unauthorized code, escalate privileges, or persist within the environment, posing a significant security threat.
Show query
| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime
from datamodel=Endpoint.Filesystem where

Filesystem.action= "created"
Filesystem.file_name IN (
    "*.bat",
    "*.cmd",
    "*.com",
    "*.dll",
    "*.exe",
    "*.js",
    "*.msc",
    "*.pif",
    "*.ps1",
    "*.sys",
    "*.vbe",
    "*.vbs"
)
Filesystem.file_path IN (
    "*:\\Temp\\*",
    "*:\\Windows\\Temp\\*",
    "*\\AppData\\Local\\Temp\\*"
)
NOT Filesystem.file_path IN ("*\\__PSScriptPolicyTest_*")

by Filesystem.action Filesystem.dest Filesystem.file_access_time
   Filesystem.file_create_time Filesystem.file_hash
   Filesystem.file_modify_time Filesystem.file_name
   Filesystem.file_path Filesystem.file_acl
   Filesystem.file_size Filesystem.process_guid
   Filesystem.process_id Filesystem.user
   Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `executables_or_script_creation_in_temp_path_filter`
Splunk ESCU SPL T1059.005 ↗
Execute Javascript With Jscript COM CLSID
The following analytic detects the execution of JavaScript using the JScript.Encode CLSID (COM Object) by cscript.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, command-line executions, and parent processes. This activity is significant as it is a known technique used by ransomware, such as Reddot, to execute malicious scripts and potentially disable AMSI (Antimalware Scan Interface). If confirmed malicious, this behavior could allow attackers to execute arbitrary code, evade detection, and maintain persistence within the environment.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name = "cscript.exe" Processes.process="*-e:{F414C262-6AC0-11CF-B6D1-00AA00BBBB58}*"
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `execute_javascript_with_jscript_com_clsid_filter`
Splunk ESCU SPL T1036.003 ↗
Execution of File with Multiple Extensions
The following analytic detects the execution of files with multiple extensions, such as ".doc.exe" or ".pdf.exe". This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process creation events where the file name contains double extensions. This activity is significant because attackers often use double extensions to disguise malicious executables as benign documents, increasing the likelihood of user execution. If confirmed malicious, this technique can lead to unauthorized code execution, potentially compromising the endpoint and allowing further malicious activities.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process IN ("*.doc.exe", "*.xls.exe","*.ppt.exe", "*.htm.exe", "*.html.exe", "*.txt.exe", "*.pdf.exe", "*.docx.exe", "*.xlsx.exe", "*.pptx.exe","*.one.exe", "*.bat.exe", "*.rtf.exe")
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `drop_dm_object_name(Processes)`
| `execution_of_file_with_multiple_extensions_filter`
Splunk ESCU SPL T1133, T1190, T1505.003 ↗
Exploit Public Facing Application via Apache Commons Text
The following analytic detects attempts to exploit the CVE-2022-42889 vulnerability in the Apache Commons Text Library, known as Text4Shell. It leverages the Web datamodel to identify suspicious HTTP requests containing specific lookup keys (url, dns, script) that can lead to Remote Code Execution (RCE). This activity is significant as it targets a critical vulnerability that can allow attackers to execute arbitrary code on the server. If confirmed malicious, this could lead to full system compromise, data exfiltration, or further lateral movement within the network.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Web
  WHERE Web.http_method IN (POST, GET)
  BY Web.src Web.status Web.uri_path
     Web.dest Web.http_method Web.uri_query
     Web.http_user_agent
| `drop_dm_object_name("Web")`
| eval utf=if(like(lower(uri_query),"%:utf-8:http%"),2,0)
| eval lookup = if(like(lower(uri_query), "%url%") OR like(lower(uri_query), "%dns%") OR like(lower(uri_query), "%script%"),2,0)
| eval other_lookups = if(like(lower(uri_query), "%env%") OR like(lower(uri_query), "%file%") OR like(lower(uri_query), "%getRuntime%") OR like(lower(uri_query), "%java%") OR like(lower(uri_query), "%localhost%") OR like(lower(uri_query), "%properties%") OR like(lower(uri_query), "%resource%") OR like(lower(uri_query), "%sys%") OR like(lower(uri_query), "%xml%") OR like(lower(uri_query), "%base%"),1,0)
| addtotals fieldname=Score utf lookup other_lookups
| fields Score, src, dest, status, uri_query, uri_path, http_method, http_user_agent firstTime lastTime
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| where Score >= 3
| `exploit_public_facing_application_via_apache_commons_text_filter`
Splunk ESCU SPL T1190, T1133 ↗
Exploit Public-Facing Fortinet FortiNAC CVE-2022-39952
The following analytic detects attempts to exploit the Fortinet FortiNAC CVE-2022-39952 vulnerability. It identifies HTTP POST requests to the URI configWizard/keyUpload.jsp with a payload.zip file. The detection leverages the Web datamodel, analyzing fields such as URL, HTTP method, and user agent. This activity is significant as it indicates an attempt to exploit a known vulnerability, potentially leading to remote code execution. If confirmed malicious, attackers could gain control over the affected system, schedule malicious tasks, and establish persistent access via a remote command and control (C2) server.
Show query
| tstats `security_content_summariesonly`
         count min(_time) as firstTime
               max(_time) as lastTime

FROM datamodel=Web WHERE

Web.url IN ("*configWizard/keyUpload.jsp*")

BY Web.http_user_agent Web.status
   Web.http_method Web.url Web.url_length
   Web.src Web.dest
| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `exploit_public_facing_fortinet_fortinac_cve_2022_39952_filter`
Splunk ESCU SPL T1190, T1133 ↗
F5 BIG-IP iControl REST Vulnerability CVE-2022-1388
The following analytic detects attempts to exploit the F5 BIG-IP iControl REST API vulnerability (CVE-2022-1388) for unauthenticated remote code execution. It identifies suspicious URI paths and POST HTTP methods, along with specific request headers containing potential commands in the `utilcmdargs` field and a random base64 encoded value in the `X-F5-Auth-Token` field. This activity is significant as it targets a critical vulnerability that can allow attackers to execute arbitrary commands on the affected system. If confirmed malicious, this could lead to full system compromise and unauthorized access to sensitive data.
Show query
| tstats `security_content_summariesonly`
         count min(_time) as firstTime
               max(_time) as lastTime
FROM datamodel=Web WHERE
Web.url="*/mgmt/tm/util/bash*"
Web.http_method="POST"
BY Web.http_user_agent Web.http_method
   Web.url Web.url_length
   Web.src Web.dest
| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `f5_big_ip_icontrol_rest_vulnerability_cve_2022_1388_filter`
Splunk ESCU SPL
F5 TMUI Authentication Bypass
The following analytic detects attempts to exploit the CVE-2023-46747 vulnerability, an authentication bypass flaw in F5 BIG-IP's Configuration utility (TMUI). It identifies this activity by monitoring for specific URI paths such as "*/mgmt/tm/auth/user/*" with the PATCH method and a 200 status code. This behavior is significant for a SOC as it indicates potential unauthorized access attempts, leading to remote code execution. If confirmed malicious, an attacker could gain unauthorized access, execute arbitrary code, steal data, disrupt systems, or conduct further malicious activities within the network.
Show query
| tstats count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Web
  WHERE Web.url IN ("*/mgmt/tm/auth/user/*") Web.http_method=PATCH Web.status=200
  BY Web.http_user_agent, Web.status Web.http_method,
     Web.url, Web.url_length, Web.src,
     Web.dest, sourcetype
| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `f5_tmui_authentication_bypass_filter`
Splunk ESCU SPL T1105 ↗
File Download or Read to Pipe Execution
The following analytic detects the use of download or file reading utilities from Windows, Linux or MacOS to download or read the contents of a file from a remote or local source and pipe it directly to a shell for execution. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions. This activity is significant as it is commonly associated with malicious actions like coinminers and exploits such as CVE-2021-44228 in Log4j. If confirmed malicious, this behavior could allow attackers to execute arbitrary code, potentially leading to system compromise and unauthorized access to sensitive data.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime

from datamodel=Endpoint.Processes where

``` This aims to cover download utilities and file reading ones ```

Processes.process IN (
  "*.DownloadFile(*",
  "*.DownloadString(*",
  "*ASCII.GetString*",
  "*bitsadmin*",
  "*certutil*",
  "*curl*",
  "*Invoke-RestMethod*",
  "*Invoke-WebRequest*",
  "*irm*",
  "*iwr *",
  "*mshta*",
  "*wget*"
)

Processes.process IN ("*|*")

(
  ``` Linux / MacOS ```
  Processes.process IN (
    "*bash*",
    "*csh*",
    "*dash*",
    "*fish*",
    "*ksh*",
    "*rbash*",
    "*tcsh*",
    "*zsh*"
  )
  OR
  ``` Because the "sh" string can overlap and is a short atom we treat it in a special case ```
  Processes.process IN (
    "*|sh"
    "* sh*"
  )
  OR
  ``` Windows ```
  Processes.process IN ("*IEX*", "*Invoke-Expression*")
)

by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
   Processes.parent_process_name Processes.parent_process_path Processes.process
   Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id
   Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user
   Processes.user_id Processes.vendor_product

| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `file_download_or_read_to_pipe_execution_filter`
Splunk ESCU SPL
File with Samsam Extension
The following analytic detects file writes with extensions indicative of a SamSam ransomware attack. It leverages file-system activity data to identify file names ending in .stubbin, .berkshire, .satoshi, .sophos, or .keyxml. This activity is significant because SamSam ransomware is highly destructive, leading to file encryption and ransom demands. If confirmed malicious, the impact includes significant financial losses, operational disruptions, and reputational damage. Immediate actions should include isolating affected systems, restoring files from backups, and investigating the attack source to prevent further incidents.
Show query
| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime
        values(Filesystem.user) as user
        values(Filesystem.dest) as dest
        values(Filesystem.file_path) as file_path
from datamodel=Endpoint.Filesystem where
Filesystem.file_name IN (
  "*.berkshire",
  "*.keyxml",
  "*.satoshi",
  "*.sophos",
  "*.stubbin"
)
by Filesystem.action Filesystem.dest Filesystem.file_access_time
   Filesystem.file_create_time Filesystem.file_hash
   Filesystem.file_modify_time Filesystem.file_name
   Filesystem.file_path Filesystem.file_acl Filesystem.file_size
   Filesystem.process_guid Filesystem.process_id
   Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(lastTime)`
| `security_content_ctime(firstTime)`
| rex field=file_name "(?<file_extension>\.[^\.]+)$"
| search file_extension IN (".berkshire", ".keyxml", ".satoshi", ".sophos", ".stubbin")
| `file_with_samsam_extension_filter`
Splunk ESCU SPL T1686 ↗
Firewall Allowed Program Enable
The following analytic detects the modification of a firewall rule to allow the execution of a specific application. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process creation events with command-line arguments related to firewall rule changes. This activity is significant as it may indicate an attempt to bypass firewall restrictions, potentially allowing unauthorized applications to communicate over the network. If confirmed malicious, this could enable an attacker to execute arbitrary code, escalate privileges, or maintain persistence within the target environment.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process = "*firewall*" Processes.process = "*allow*" Processes.process = "*add*" Processes.process = "*ENABLE*"
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `firewall_allowed_program_enable_filter`
Splunk ESCU SPL T1068 ↗
First Time Seen Child Process of Zoom
The following analytic identifies the first-time execution of child processes spawned by Zoom (zoom.exe or zoom.us). It leverages Endpoint Detection and Response (EDR) data, specifically monitoring process creation events and comparing them against previously seen child processes. This activity is significant because the execution of unfamiliar child processes by Zoom could indicate malicious exploitation or misuse of the application. If confirmed malicious, this could lead to unauthorized code execution, data exfiltration, or further compromise of the endpoint.
Show query
| tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime values(Processes.user) as user values(Processes.action) as action values(Processes.dest) as dest values(Processes.original_file_name) as original_file_name values(Processes.parent_process) as parent_process values(Processes.parent_process_exec) as parent_process_exec values(Processes.parent_process_guid) as parent_process_guid values(Processes.parent_process_id) as parent_process_id values(Processes.parent_process_name) as parent_process_name values(Processes.parent_process_path) as parent_process_path values(Processes.process) as process values(Processes.process_exec) as process_exec values(Processes.process_guid) as process_guid values(Processes.process_hash) as process_hash values(Processes.process_integrity_level) as process_integrity_level values(Processes.process_name) as process_name values(Processes.process_path) as process_path  values(Processes.user_id) as user_id values(Processes.vendor_product) as vendor_product FROM datamodel=Endpoint.Processes
  WHERE (
        Processes.parent_process_name=zoom.exe
        OR
        Processes.parent_process_name=zoom.us
    )
  BY Processes.process_id Processes.dest
| `drop_dm_object_name(Processes)`
| lookup zoom_first_time_child_process dest as dest process_name as process_name OUTPUT firstTimeSeen
| where isnull(firstTimeSeen) OR firstTimeSeen > relative_time(now(), "`previously_seen_zoom_child_processes_window`")
| `security_content_ctime(firstTime)`
| `first_time_seen_child_process_of_zoom_filter`
Splunk ESCU SPL T1569.002 ↗
First Time Seen Running Windows Service
The following analytic detects the first occurrence of a Windows service running in your environment. It leverages Windows system event logs, specifically EventCode 7036, to identify services entering the "running" state. This activity is significant because the appearance of a new or previously unseen service could indicate the installation of unauthorized or malicious software. If confirmed malicious, this activity could allow an attacker to execute arbitrary code, maintain persistence, or escalate privileges within the environment. Monitoring for new services helps in early detection of potential threats.
Show query
`wineventlog_system` EventCode=7036
  | rex field=Message "The (?<service>[-\(\)\s\w]+) service entered the (?<state>\w+) state"
  | where state="running"
  | lookup previously_seen_running_windows_services service as service OUTPUT firstTimeSeen
  | where isnull(firstTimeSeen) OR firstTimeSeen > relative_time(now(), `previously_seen_windows_services_window`)
  | table _time dest service
  | `first_time_seen_running_windows_service_filter`
Splunk ESCU SPL T1112, T1548.002 ↗
FodHelper UAC Bypass
The following analytic detects the execution of fodhelper.exe, which is known to exploit a User Account Control (UAC) bypass by leveraging specific registry keys. The detection method uses Endpoint Detection and Response (EDR) telemetry to identify when fodhelper.exe spawns a child process and accesses the registry keys. This activity is significant because it indicates a potential privilege escalation attempt by an attacker. If confirmed malicious, the attacker could execute commands with elevated privileges, leading to unauthorized system changes and potential full system compromise.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.parent_process_name=fodhelper.exe
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `fodhelper_uac_bypass_filter`
Splunk ESCU SPL T1190, T1133 ↗
Fortinet Appliance Auth bypass
The following analytic detects attempts to exploit CVE-2022-40684, a Fortinet appliance authentication bypass vulnerability. It identifies REST API requests to the /api/v2/ endpoint using various HTTP methods (GET, POST, PUT, DELETE) that may indicate unauthorized modifications, such as adding SSH keys or creating new users. This detection leverages the Web datamodel to monitor specific URL patterns and HTTP methods. This activity is significant as it can lead to unauthorized access and control over the appliance. If confirmed malicious, attackers could gain persistent access, reroute network traffic, or capture sensitive information.
Show query
| tstats `security_content_summariesonly`
         count min(_time) as firstTime
               max(_time) as lastTime

FROM datamodel=Web WHERE

Web.url = "*/api/v2/cmdb/system/admin*"
Web.http_method IN ("GET", "PUT")
BY Web.http_user_agent
   Web.http_method Web.url
   Web.url_length
   Web.src Web.dest
| `drop_dm_object_name("Web")`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `fortinet_appliance_auth_bypass_filter`
Splunk ESCU SPL T1070 ↗
Fsutil Zeroing File
The following analytic detects the execution of the 'fsutil' command with the 'setzerodata' parameter, which zeros out a target file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant because it is a technique used by ransomware, such as LockBit, to evade detection by erasing its malware path after encrypting the host. If confirmed malicious, this action could hinder forensic investigations and allow attackers to cover their tracks, complicating incident response efforts.
Show query
| tstats `security_content_summariesonly` count values(Processes.process) as process values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name=fsutil.exe Processes.process="*setzerodata*"
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `fsutil_zeroing_file_filter`
GCP Authentication Failed During MFA Challenge
The following analytic detects failed authentication attempts during the Multi-Factor Authentication (MFA) challenge on a Google Cloud Platform (GCP) tenant. It uses Google Workspace login failure events to identify instances where MFA methods were challenged but not successfully completed. This activity is significant as it may indicate an adversary attempting to access an account with compromised credentials despite MFA protection. If confirmed malicious, this could lead to unauthorized access attempts, potentially compromising sensitive data and resources within the GCP environment.
Show query
`gws_reports_login` event.name=login_failure `gws_login_mfa_methods`
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY user, src_ip, login_challenge_method
  | `gcp_authentication_failed_during_mfa_challenge_filter`
Splunk ESCU SPL T1078 ↗
GCP Detect gcploit framework
The following analytic identifies the use of the GCPloit exploitation framework within Google Cloud Platform (GCP). It detects specific GCP Pub/Sub messages with a function timeout of 539 seconds, which is indicative of GCPloit activity. This detection is significant as GCPloit can be used to escalate privileges and facilitate lateral movement from compromised high-privilege accounts. If confirmed malicious, this activity could allow attackers to gain unauthorized access, escalate their privileges, and move laterally within the GCP environment, potentially compromising sensitive data and critical resources.
Show query
`google_gcp_pubsub_message` data.protoPayload.request.function.timeout=539s
  | table src src_user data.resource.labels.project_id data.protoPayload.request.function.serviceAccountEmail data.protoPayload.authorizationInfo{}.permission data.protoPayload.request.location http_user_agent
  | `gcp_detect_gcploit_framework_filter`
Splunk ESCU SPL T1526 ↗
GCP Kubernetes cluster pod scan detection
The following analytic identifies unauthenticated requests to Kubernetes cluster pods. It detects this activity by analyzing GCP Pub/Sub messages for audit logs where the response status code is 401, indicating unauthorized access attempts. This activity is significant for a SOC because it may indicate reconnaissance or scanning attempts by an attacker trying to identify vulnerable pods. If confirmed malicious, this activity could lead to unauthorized access, allowing the attacker to exploit vulnerabilities within the cluster, potentially compromising sensitive data or gaining control over the Kubernetes environment.
Show query
`google_gcp_pubsub_message` category=kube-audit
  | spath input=properties.log
  | search responseStatus.code=401
  | table sourceIPs{} userAgent verb requestURI responseStatus.reason properties.pod
  | `gcp_kubernetes_cluster_pod_scan_detection_filter`
Splunk ESCU SPL T1556.006, T1586.003 ↗
GCP Multi-Factor Authentication Disabled
The following analytic detects an attempt to disable multi-factor authentication (MFA) for a Google Cloud Platform (GCP) user. It leverages Google Workspace Admin log events, specifically the `UNENROLL_USER_FROM_STRONG_AUTH` command. This activity is significant because disabling MFA can allow an adversary to maintain persistence within the environment using a compromised account without raising suspicion. If confirmed malicious, this action could enable attackers to bypass additional security layers, potentially leading to unauthorized access, data exfiltration, or further exploitation of the compromised account.
Show query
`gws_reports_admin` command=UNENROLL_USER_FROM_STRONG_AUTH
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY user, command, actor.email,
       status, id.applicationName, event.name,
       vendor_account, action
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `gcp_multi_factor_authentication_disabled_filter`
GCP Multiple Failed MFA Requests For User
The following analytic detects multiple failed multi-factor authentication (MFA) requests for a single user within a Google Cloud Platform (GCP) tenant. It triggers when 10 or more MFA prompts fail within a 5-minute window, using Google Workspace login failure events. This behavior is significant as it may indicate an adversary attempting to bypass MFA by bombarding the user with repeated authentication requests. If confirmed malicious, this activity could lead to unauthorized access, allowing attackers to compromise accounts and potentially escalate privileges within the GCP environment.
Show query
`gws_reports_login` event.name=login_failure `gws_login_mfa_methods`
  | bucket span=5m _time
  | stats dc(_raw) AS mfa_prompts values(user) AS user
    BY src_ip, login_challenge_method, _time
  | where mfa_prompts >= 10
  | `gcp_multiple_failed_mfa_requests_for_user_filter`
GCP Multiple Users Failing To Authenticate From Ip
The following analytic detects a single source IP address failing to authenticate into more than 20 unique Google Workspace user accounts within a 5-minute window. It leverages Google Workspace login failure events to identify potential password spraying attacks. This activity is significant as it may indicate an adversary attempting to gain unauthorized access or elevate privileges within the Google Cloud Platform. If confirmed malicious, this behavior could lead to unauthorized access to sensitive resources, data breaches, or further exploitation within the environment.
Show query
`gws_reports_login` event.type = login event.name = login_failure
  | bucket span=5m _time
  | stats count dc(user) AS unique_accounts values(user) as tried_accounts values(authentication_method) AS authentication_method earliest(_time) as firstTime latest(_time) as lastTime
    BY _time event.name src
       app id.applicationName
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | where unique_accounts > 20
  | `gcp_multiple_users_failing_to_authenticate_from_ip_filter`
Splunk ESCU SPL T1078.004, T1586.003 ↗
GCP Successful Single-Factor Authentication
The following analytic identifies a successful single-factor authentication event against Google Cloud Platform (GCP) for an account without Multi-Factor Authentication (MFA) enabled. It uses Google Workspace login event data to detect instances where MFA is not utilized. This activity is significant as it may indicate a misconfiguration, policy violation, or potential account takeover attempt. If confirmed malicious, an attacker could gain unauthorized access to GCP resources, potentially leading to data breaches, service disruptions, or further exploitation within the cloud environment.
Show query
`gws_reports_login` event.name=login_success NOT `gws_login_mfa_methods`
  | stats count min(_time) as firstTime max(_time) as lastTime
    BY user, src_ip, login_challenge_method,
       app, event.name, vendor_account,
       action
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `gcp_successful_single_factor_authentication_filter`
GCP Unusual Number of Failed Authentications From Ip
The following analytic identifies a single source IP failing to authenticate into Google Workspace with multiple valid users, potentially indicating a Password Spraying attack. It uses Google Workspace login failure events and calculates the standard deviation for source IPs, applying the 3-sigma rule to detect unusual failed authentication attempts. This activity is significant as it may signal an adversary attempting to gain initial access or elevate privileges. If confirmed malicious, this could lead to unauthorized access, data breaches, or further exploitation within the environment.
Show query
`gws_reports_login` event.type = login event.name = login_failure
  | bucket span=5m _time
  | stats  dc(user_name) AS unique_accounts values(user_name) as tried_accounts values(authentication_method) AS authentication_method
    BY _time, src
  | eventstats  avg(unique_accounts) as ip_avg , stdev(unique_accounts) as ip_std
    BY _time
  | eval  upperBound=(ip_avg+ip_std*3)
  | eval  isOutlier=if(unique_accounts > 10 and unique_accounts >= upperBound, 1, 0)
  | where isOutlier =1
  | `gcp_unusual_number_of_failed_authentications_from_ip_filter`
Splunk ESCU SPL T1055 ↗
GPUpdate with no Command Line Arguments with Network
The following analytic detects the execution of gpupdate.exe without command line arguments and with an active network connection. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on process execution and network traffic data. It is significant because gpupdate.exe typically runs with specific arguments, and its execution without them, especially with network activity, is often associated with malicious software like Cobalt Strike. If confirmed malicious, this activity could indicate an attacker leveraging gpupdate.exe for lateral movement, command and control, or other nefarious purposes, potentially leading to system compromise.
Show query
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name=gpupdate.exe
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| regex process="(?i)(gpupdate\.exe.{0,4}$)"
| join process_id dest [
| tstats `security_content_summariesonly` count values(All_Traffic.app) as app values(All_Traffic.dest_ip) as dest_ip values(All_Traffic.direction) as direction values(All_Traffic.dvc) as dvc values(All_Traffic.protocol) as protocol values(All_Traffic.protocol_version) as protocol_version values(All_Traffic.src) as src values(All_Traffic.src_ip) as src_ip values(All_Traffic.src_port) as src_port values(All_Traffic.transport) as transport FROM datamodel=Network_Traffic.All_Traffic
  WHERE All_Traffic.dest_port != 0
  BY All_Traffic.process_id All_Traffic.src All_Traffic.dest All_Traffic.dest_port
| `drop_dm_object_name(All_Traffic)`
| rename dest as C2
| rename src as dest ]
| table _time user dest parent_process_name process_name process_path process process_id dest_port C2 app dest_ip direction dvc protocol protocol_version src src_ip src_port transport
| `gpupdate_with_no_command_line_arguments_with_network_filter`
Splunk ESCU SPL T1566.001 ↗
GSuite Email Suspicious Attachment
The following analytic detects suspicious attachment file extensions in GSuite emails, potentially indicating a spear-phishing attack. It leverages GSuite Gmail logs to identify emails with attachments having file extensions commonly associated with malware, such as .exe, .bat, and .js. This activity is significant as these file types are often used to deliver malicious payloads, posing a risk of compromising targeted machines. If confirmed malicious, this could lead to unauthorized code execution, data breaches, or further network infiltration.
Show query
`gsuite_gmail` "attachment{}.file_extension_type" IN ("pl", "py", "rb", "sh", "bat", "exe", "dll", "cpl", "com", "js", "vbs", "ps1", "reg","swf", "cmd", "go")
  | eval phase="plan"
  | eval severity="medium"
  | stats count min(_time) as firstTime max(_time) as lastTime values(attachment{}.file_extension_type) as email_attachments, values(attachment{}.sha256) as attachment_sha256, values(payload_size) as payload_size
    BY destination{}.service num_message_attachments subject
       destination{}.address source.address phase
       severity
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `gsuite_email_suspicious_attachment_filter`
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