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Deployable detection rules

6 vendor-native detections · ready to paste into your SIEM · cross-linked to ATT&CK
technique T1049 ×

Detections

6 shown of 6
Splunk ESCU SPL T1049 ↗
GetNetTcpconnection with PowerShell
The following analytic identifies the execution of `powershell.exe` with the `Get-NetTcpConnection` command, which lists current TCP connections on a system. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. Monitoring this activity is significant as it may indicate an adversary or Red Team performing network reconnaissance or situational awareness. If confirmed malicious, this activity could allow attackers to map network connections, aiding in lateral movement or further exploitation within the network.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE (
        Processes.process_name="powershell.exe"
    )
    (Processes.process=*Get-NetTcpConnection*)
  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)`
| `getnettcpconnection_with_powershell_filter`
Splunk ESCU SPL T1049 ↗
GetNetTcpconnection with PowerShell Script Block
The following analytic detects the execution of the `Get-NetTcpconnection` PowerShell cmdlet using PowerShell Script Block Logging (EventCode=4104). This cmdlet lists network connections on a system, which adversaries may use for situational awareness and Active Directory discovery. Monitoring this activity is crucial as it can indicate reconnaissance efforts by an attacker. If confirmed malicious, this behavior could allow an attacker to map the network, identify critical systems, and plan further attacks, potentially leading to data exfiltration or lateral movement within the network.
Show query
`powershell` EventCode=4104 (ScriptBlockText = "*Get-NetTcpconnection*")
  | 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)`
  | `getnettcpconnection_with_powershell_script_block_filter`
Splunk ESCU SPL T1049 ↗
Network Connection Discovery With Arp
The following analytic detects the execution of `arp.exe` with the `-a` flag, which is used to list network connections on a compromised system. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, command-line executions, and related telemetry. Monitoring this activity is significant because both Red Teams and adversaries use `arp.exe` for situational awareness and Active Directory discovery. If confirmed malicious, this activity could allow attackers to map the network, identify active devices, and plan further lateral movement or attacks.
Show query
| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime

FROM datamodel=Endpoint.Processes WHERE

(
    Processes.process_name="arp.exe"
    OR
    Processes.process_original_file_name="arp.exe"
)
Processes.process IN (
    "* -a*",
    "* -g *",
    "* /a *",
    "* /g *"
)
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)`
| `network_connection_discovery_with_arp_filter`
Splunk ESCU SPL T1049 ↗
Network Connection Discovery With Netstat
The following analytic detects the execution of `netstat.exe` with command-line arguments to list network connections on a system. 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 both Red Teams and adversaries use `netstat.exe` for situational awareness and Active Directory discovery. If confirmed malicious, this behavior could allow attackers to map network connections, identify critical systems, and plan further lateral movement or data exfiltration.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE (
        Processes.process_name="netstat.exe"
    )
    (Processes.process=*-a*)
  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)`
| `network_connection_discovery_with_netstat_filter`
Splunk ESCU SPL T1049 ↗
Windows Network Connection Discovery Via Net
The following analytic identifies the execution of `net.exe` with command-line arguments used to list or display information about computer connections. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential network reconnaissance by adversaries or Red Teams, aiming to gather situational awareness and Active Directory information. If confirmed malicious, this behavior could allow attackers to map the network, identify critical assets, and plan further attacks, potentially leading to data exfiltration or lateral movement.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE (
        `process_net`
        OR
        (Processes.process_name="net.exe"
        OR
        Processes.original_file_name="net.exe")
    )
    AND (Processes.process=*use)
  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)`
| `windows_network_connection_discovery_via_net_filter`
Splunk ESCU SPL T1049 ↗
Windows System Network Connections Discovery Netsh
The following analytic detects the execution of the Windows built-in tool netsh.exe to display the state, configuration, and profile of the host firewall. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process metadata. Monitoring this activity is crucial as netsh.exe can be used by adversaries to bypass firewall rules or discover firewall settings. If confirmed malicious, this activity could allow attackers to manipulate firewall configurations, potentially leading to unauthorized network access or data exfiltration.
Show query
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE `process_netsh`AND Processes.process = "* show *" Processes.process IN ("*state*", "*config*", "*wlan*", "*profile*")
  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)`
| `windows_system_network_connections_discovery_netsh_filter`
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