title: Communication To Ngrok Tunneling Service - Linux
id: 19bf6fdb-7721-4f3d-867f-53467f6a5db6
status: test
description: Detects an executable accessing an ngrok tunneling endpoint, which could be a sign of forbidden exfiltration of data exfiltration by malicious actors
references:
    - https://twitter.com/hakluke/status/1587733971814977537/photo/1
    - https://ngrok.com/docs/secure-tunnels/tunnels/ssh-reverse-tunnel-agent
author: Florian Roth (Nextron Systems)
date: 2022-11-03
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1568.002
    - attack.t1572
    - attack.t1090
    - attack.t1102
    - attack.s0508
logsource:
    product: linux
    category: network_connection
detection:
    selection:
        DestinationHostname|contains:
            - 'tunnel.us.ngrok.com'
            - 'tunnel.eu.ngrok.com'
            - 'tunnel.ap.ngrok.com'
            - 'tunnel.au.ngrok.com'
            - 'tunnel.sa.ngrok.com'
            - 'tunnel.jp.ngrok.com'
            - 'tunnel.in.ngrok.com'
    condition: selection
falsepositives:
    - Legitimate use of ngrok
level: high

title: Communication To Ngrok Tunneling Service Initiated
id: 1d08ac94-400d-4469-a82f-daee9a908849
related:
    - id: 18249279-932f-45e2-b37a-8925f2597670
      type: similar
status: test
description: |
    Detects an executable initiating a network connection to "ngrok" tunneling domains.
    Attackers were seen using this "ngrok" in order to store their second stage payloads and malware.
    While communication with such domains can be legitimate, often times is a sign of either data exfiltration by malicious actors or additional download.
references:
    - https://twitter.com/hakluke/status/1587733971814977537/photo/1
    - https://ngrok.com/docs/secure-tunnels/tunnels/ssh-reverse-tunnel-agent
author: Florian Roth (Nextron Systems)
date: 2022-11-03
modified: 2024-02-02
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1568.002
    - attack.t1572
    - attack.t1090
    - attack.t1102
    - attack.s0508
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        DestinationHostname|contains:
            - 'tunnel.us.ngrok.com'
            - 'tunnel.eu.ngrok.com'
            - 'tunnel.ap.ngrok.com'
            - 'tunnel.au.ngrok.com'
            - 'tunnel.sa.ngrok.com'
            - 'tunnel.jp.ngrok.com'
            - 'tunnel.in.ngrok.com'
    condition: selection
falsepositives:
    - Legitimate use of the ngrok service.
level: high

title: DNS Query for Anonfiles.com Domain - DNS Client
id: 29f171d7-aa47-42c7-9c7b-3c87938164d9
related:
    - id: 065cceea-77ec-4030-9052-fc0affea7110
      type: similar
status: test
description: Detects DNS queries for anonfiles.com, which is an anonymous file upload platform often used for malicious purposes
references:
    - https://www.trendmicro.com/vinfo/us/security/news/ransomware-spotlight/ransomware-spotlight-blackbyte
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-16
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    service: dns-client
    definition: 'Requirements: Microsoft-Windows-DNS Client Events/Operational Event Log must be enabled/collected in order to receive the events.'
detection:
    selection:
        EventID: 3008
        QueryName|contains: '.anonfiles.com'
    condition: selection
falsepositives:
    - Rare legitimate access to anonfiles.com
level: high

title: DNS Query for Anonfiles.com Domain - Sysmon
id: 065cceea-77ec-4030-9052-fc0affea7110
related:
    - id: 29f171d7-aa47-42c7-9c7b-3c87938164d9
      type: similar
status: test
description: Detects DNS queries for "anonfiles.com", which is an anonymous file upload platform often used for malicious purposes
references:
    - https://www.trendmicro.com/vinfo/us/security/news/ransomware-spotlight/ransomware-spotlight-blackbyte
author: pH-T (Nextron Systems)
date: 2022-07-15
modified: 2023-01-16
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    category: dns_query
detection:
    selection:
        QueryName|contains: '.anonfiles.com'
    condition: selection
falsepositives:
    - Rare legitimate access to anonfiles.com
level: high

title: Monero Crypto Coin Mining Pool Lookup
id: b593fd50-7335-4682-a36c-4edcb68e4641
status: stable
description: Detects suspicious DNS queries to Monero mining pools
references:
    - https://www.nextron-systems.com/2021/10/24/monero-mining-pool-fqdns/
author: Florian Roth (Nextron Systems)
date: 2021-10-24
tags:
    - attack.impact
    - attack.t1496
    - attack.exfiltration
    - attack.t1567
logsource:
    category: dns
detection:
    selection:
        query|contains:
            - 'pool.minexmr.com'
            - 'fr.minexmr.com'
            - 'de.minexmr.com'
            - 'sg.minexmr.com'
            - 'ca.minexmr.com'
            - 'us-west.minexmr.com'
            - 'pool.supportxmr.com'
            - 'mine.c3pool.com'
            - 'xmr-eu1.nanopool.org'
            - 'xmr-eu2.nanopool.org'
            - 'xmr-us-east1.nanopool.org'
            - 'xmr-us-west1.nanopool.org'
            - 'xmr-asia1.nanopool.org'
            - 'xmr-jp1.nanopool.org'
            - 'xmr-au1.nanopool.org'
            - 'xmr.2miners.com'
            - 'xmr.hashcity.org'
            - 'xmr.f2pool.com'
            - 'xmrpool.eu'
            - 'pool.hashvault.pro'
    condition: selection
falsepositives:
    - Legitimate crypto coin mining
level: high

title: PUA - Rclone Execution
id: e37db05d-d1f9-49c8-b464-cee1a4b11638
related:
    - id: a0d63692-a531-4912-ad39-4393325b2a9c
      type: obsolete
    - id: cb7286ba-f207-44ab-b9e6-760d82b84253
      type: obsolete
status: test
description: Detects execution of RClone utility for exfiltration as used by various ransomwares strains like REvil, Conti, FiveHands, etc
references:
    - https://research.nccgroup.com/2021/05/27/detecting-rclone-an-effective-tool-for-exfiltration/
    - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware
    - https://us-cert.cisa.gov/ncas/analysis-reports/ar21-126a
    - https://labs.sentinelone.com/egregor-raas-continues-the-chaos-with-cobalt-strike-and-rclone
    - https://www.splunk.com/en_us/blog/security/darkside-ransomware-splunk-threat-update-and-detections.html
author: Bhabesh Raj, Sittikorn S, Aaron Greetham (@beardofbinary) - NCC Group
date: 2021-05-10
modified: 2023-03-05
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    category: process_creation
detection:
    selection_specific_options:
        CommandLine|contains|all:
            - '--config '
            - '--no-check-certificate '
            - ' copy '
    selection_rclone_img:
        - Image|endswith: '\rclone.exe'
        - Description: 'Rsync for cloud storage'
    selection_rclone_cli:
        CommandLine|contains:
            - 'pass'
            - 'user'
            - 'copy'
            - 'sync'
            - 'config'
            - 'lsd'
            - 'remote'
            - 'ls'
            - 'mega'
            - 'pcloud'
            - 'ftp'
            - 'ignore-existing'
            - 'auto-confirm'
            - 'transfers'
            - 'multi-thread-streams'
            - 'no-check-certificate '
    condition: selection_specific_options or all of selection_rclone_*
falsepositives:
    - Unknown
level: high

title: PUA - Restic Backup Tool Execution
id: 6ddff2e8-ea1a-45d0-8938-93dfc1d67ae7
status: experimental
description: |
    Detects the execution of the Restic backup tool, which can be used for data exfiltration.
    Threat actors may leverage Restic to back up and exfiltrate sensitive data to remote storage locations, including cloud services.
    If not legitimately used in the enterprise environment, its presence may indicate malicious activity.
references:
    - https://thedfirreport.com/2024/09/30/nitrogen-campaign-drops-sliver-and-ends-with-blackcat-ransomware/#exfiltration
    - https://restic.net/
    - https://restic.readthedocs.io/en/stable/030_preparing_a_new_repo.html
author: Nounou Mbeiri, Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2025-10-17
tags:
    - attack.exfiltration
    - attack.t1048
    - attack.t1567.002
logsource:
    product: windows
    category: process_creation
detection:
    selection_specific:
        - CommandLine|contains|all:
              - '--password-file'
              - 'init'
              - ' -r '
        - CommandLine|contains|all:
              - '--use-fs-snapshot'
              - 'backup'
              - ' -r '
    selection_restic:
        CommandLine|contains:
            - 'sftp:'
            - 'rest:http'
            - 's3:s3.'
            - 's3.http'
            - 'azure:'
            - ' gs:'
            - 'rclone:'
            - 'swift:'
            - ' b2:'
        CommandLine|contains|all:
            - ' init '
            - ' -r '
    condition: 1 of selection_*
falsepositives:
    - Legitimate use of Restic for backup purposes within the organization.
level: high

title: Process Initiated Network Connection To Ngrok Domain
id: 18249279-932f-45e2-b37a-8925f2597670
related:
    - id: 1d08ac94-400d-4469-a82f-daee9a908849
      type: similar
status: test
description: |
    Detects an executable initiating a network connection to "ngrok" domains.
    Attackers were seen using this "ngrok" in order to store their second stage payloads and malware.
    While communication with such domains can be legitimate, often times is a sign of either data exfiltration by malicious actors or additional download.
references:
    - https://ngrok.com/
    - https://ngrok.com/blog-post/new-ngrok-domains
    - https://www.virustotal.com/gui/file/cca0c1182ac114b44dc52dd2058fcd38611c20bb6b5ad84710681d38212f835a/
    - https://www.rnbo.gov.ua/files/2023_YEAR/CYBERCENTER/november/APT29%20attacks%20Embassies%20using%20CVE-2023-38831%20-%20report%20en.pdf
author: Florian Roth (Nextron Systems)
date: 2022-07-16
modified: 2025-07-30
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1572
    - attack.t1102
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - '.ngrok-free.app'
            - '.ngrok-free.dev'
            - '.ngrok.app'
            - '.ngrok.dev'
            - '.ngrok.io'
    condition: selection
falsepositives:
    - Legitimate use of the ngrok service.
# Note: The level of this rule is related to your internal policy.
level: high

title: Suspicious Dropbox API Usage
id: 25eabf56-22f0-4915-a1ed-056b8dae0a68
status: test
description: Detects an executable that isn't dropbox but communicates with the Dropbox API
references:
    - https://app.any.run/tasks/7e906adc-9d11-447f-8641-5f40375ecebb
    - https://www.zscaler.com/blogs/security-research/new-espionage-attack-molerats-apt-targeting-users-middle-east
author: Florian Roth (Nextron Systems)
date: 2022-04-20
tags:
    - attack.command-and-control
    - attack.exfiltration
    - attack.t1105
    - attack.t1567.002
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - 'api.dropboxapi.com'
            - 'content.dropboxapi.com'
    filter_main_legit_dropbox:
        # Note: It's better to add a specific path to the exact location(s) where dropbox is installed
        Image|contains: '\Dropbox'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate use of the API with a tool that the author wasn't aware of
level: high

title: Arbitrary File Download Via ConfigSecurityPolicy.EXE
id: 1f0f6176-6482-4027-b151-00071af39d7e
status: test
description: |
    Detects the execution of "ConfigSecurityPolicy.EXE", a binary part of Windows Defender used to manage settings in Windows Defender.
    Users can configure different pilot collections for each of the co-management workloads.
    It can be abused by attackers in order to upload or download files.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/ConfigSecurityPolicy/
author: frack113
date: 2021-11-26
modified: 2022-05-16
tags:
    - attack.exfiltration
    - attack.t1567
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - CommandLine|contains: ConfigSecurityPolicy.exe
        - Image|endswith: '\ConfigSecurityPolicy.exe'
        - OriginalFileName: 'ConfigSecurityPolicy.exe'
    selection_url:
        CommandLine|contains:
            - 'ftp://'
            - 'http://'
            - 'https://'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

title: DNS Query To MEGA Hosting Website
id: 613c03ba-0779-4a53-8a1f-47f914a4ded3
related:
    - id: 66474410-b883-415f-9f8d-75345a0a66a6
      type: similar
status: test
description: Detects DNS queries for subdomains related to MEGA sharing website
references:
    - https://research.nccgroup.com/2021/05/27/detecting-rclone-an-effective-tool-for-exfiltration/
author: Aaron Greetham (@beardofbinary) - NCC Group
date: 2021-05-26
modified: 2023-09-18
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    category: dns_query
detection:
    selection:
        QueryName|contains: 'userstorage.mega.co.nz'
    condition: selection
falsepositives:
    - Legitimate DNS queries and usage of Mega
level: medium

title: DNS Query To MEGA Hosting Website - DNS Client
id: 66474410-b883-415f-9f8d-75345a0a66a6
related:
    - id: 613c03ba-0779-4a53-8a1f-47f914a4ded3
      type: similar
status: test
description: Detects DNS queries for subdomains related to MEGA sharing website
references:
    - https://research.nccgroup.com/2021/05/27/detecting-rclone-an-effective-tool-for-exfiltration/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-16
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    service: dns-client
    definition: 'Requirements: Microsoft-Windows-DNS Client Events/Operational Event Log must be enabled/collected in order to receive the events.'
detection:
    selection:
        EventID: 3008
        QueryName|contains: 'userstorage.mega.co.nz'
    condition: selection
falsepositives:
    - Legitimate DNS queries and usage of Mega
level: medium

title: LOLBAS Data Exfiltration by DataSvcUtil.exe
id: e290b10b-1023-4452-a4a9-eb31a9013b3a
status: test
description: Detects when a user performs data exfiltration by using DataSvcUtil.exe
references:
    - https://gist.github.com/teixeira0xfffff/837e5bfed0d1b0a29a7cb1e5dbdd9ca6
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/wcf-data-service-client-utility-datasvcutil-exe
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/generating-the-data-service-client-library-wcf-data-services
    - https://learn.microsoft.com/en-us/previous-versions/dotnet/framework/data/wcf/how-to-add-a-data-service-reference-wcf-data-services
    - https://lolbas-project.github.io/lolbas/Binaries/DataSvcUtil/
author: Ialle Teixeira @teixeira0xfffff, Austin Songer @austinsonger
date: 2021-09-30
modified: 2022-05-16
tags:
    - attack.exfiltration
    - attack.t1567
logsource:
    category: process_creation
    product: windows
detection:
    selection_cli:
        CommandLine|contains:
            - '/in:'
            - '/out:'
            - '/uri:'
    selection_img:
        - Image|endswith: '\DataSvcUtil.exe'
        - OriginalFileName: 'DataSvcUtil.exe'
    condition: all of selection*
falsepositives:
    - DataSvcUtil.exe being used may be performed by a system administrator.
    - Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - DataSvcUtil.exe being executed from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

title: Network Connection Initiated To BTunnels Domains
id: 9e02c8ec-02b9-43e8-81eb-34a475ba7965
status: test
description: |
    Detects network connections to BTunnels domains initiated by a process on the system.
    Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
    - https://defr0ggy.github.io/research/Utilizing-BTunnel-For-Data-Exfiltration/
author: Kamran Saifullah
date: 2024-09-13
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1572
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith: '.btunnel.co.in'
    condition: selection
falsepositives:
    - Legitimate use of BTunnels will also trigger this.
level: medium

title: Network Connection Initiated To Cloudflared Tunnels Domains
id: 7cd1dcdc-6edf-4896-86dc-d1f19ad64903
related:
    - id: a1d9eec5-33b2-4177-8d24-27fe754d0812
      type: derived
status: test
description: |
    Detects network connections to Cloudflared tunnels domains initiated by a process on the system.
    Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
    - https://defr0ggy.github.io/research/Abusing-Cloudflared-A-Proxy-Service-To-Host-Share-Applications/
    - https://www.guidepointsecurity.com/blog/tunnel-vision-cloudflared-abused-in-the-wild/
    - Internal Research
author: Kamran Saifullah, Nasreddine Bencherchali (Nextron Systems)
date: 2024-05-27
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1572
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - '.v2.argotunnel.com'
            - 'protocol-v2.argotunnel.com'
            - 'trycloudflare.com'
            - 'update.argotunnel.com'
    condition: selection
falsepositives:
    - Legitimate use of cloudflare tunnels will also trigger this.
level: medium

title: Network Connection Initiated To DevTunnels Domain
id: 9501f8e6-8e3d-48fc-a8a6-1089dd5d7ef4
related:
    - id: 4b657234-038e-4ad5-997c-4be42340bce4 # Net Connection VsCode
      type: similar
    - id: b3e6418f-7c7a-4fad-993a-93b65027a9f1 # DNS VsCode
      type: similar
    - id: 1cb0c6ce-3d00-44fc-ab9c-6d6d577bf20b # DNS DevTunnels
      type: similar
status: test
description: |
    Detects network connections to Devtunnels domains initiated by a process on a system. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
    - https://blueteamops.medium.com/detecting-dev-tunnels-16f0994dc3e2
    - https://learn.microsoft.com/en-us/azure/developer/dev-tunnels/security
    - https://cydefops.com/devtunnels-unleashed
author: Kamran Saifullah
date: 2023-11-20
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567.001
    - attack.t1572
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith: '.devtunnels.ms'
    condition: selection
falsepositives:
    - Legitimate use of Devtunnels will also trigger this.
level: medium

title: Network Connection Initiated To Visual Studio Code Tunnels Domain
id: 4b657234-038e-4ad5-997c-4be42340bce4
related:
    - id: 9501f8e6-8e3d-48fc-a8a6-1089dd5d7ef4 # Net Connection DevTunnels
      type: similar
    - id: b3e6418f-7c7a-4fad-993a-93b65027a9f1 # DNS VsCode
      type: similar
    - id: 1cb0c6ce-3d00-44fc-ab9c-6d6d577bf20b # DNS DevTunnels
      type: similar
status: test
description: |
    Detects network connections to Visual Studio Code tunnel domains initiated by a process on a system. Attackers can abuse that feature to establish a reverse shell or persistence on a machine.
references:
    - https://ipfyx.fr/post/visual-studio-code-tunnel/
    - https://badoption.eu/blog/2023/01/31/code_c2.html
    - https://cydefops.com/vscode-data-exfiltration
author: Kamran Saifullah
date: 2023-11-20
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1572
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith: '.tunnels.api.visualstudio.com'
    condition: selection
falsepositives:
    - Legitimate use of Visual Studio Code tunnel will also trigger this.
level: medium

title: Rclone Activity via Proxy
id: 2c03648b-e081-41a5-b9fb-7d854a915091
status: test
description: Detects the use of rclone, a command-line program to manage files on cloud storage, via its default user-agent string
references:
    - https://rclone.org/
    - https://www.kroll.com/en/insights/publications/cyber/new-m365-business-email-compromise-attacks-with-rclone
author: Janantha Marasinghe
date: 2022-10-18
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    category: proxy
detection:
    selection:
        c-useragent|startswith: 'rclone/v'
    condition: selection
falsepositives:
    - Valid requests with this exact user agent to that is used by legitimate scripts or sysadmin operations
level: medium

title: Rclone Config File Creation
id: 34986307-b7f4-49be-92f3-e7a4d01ac5db
status: test
description: Detects Rclone config files being created
references:
    - https://research.nccgroup.com/2021/05/27/detecting-rclone-an-effective-tool-for-exfiltration/
author: Aaron Greetham (@beardofbinary) - NCC Group
date: 2021-05-26
modified: 2023-05-09
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    category: file_event
detection:
    selection:
        TargetFilename|contains|all:
            - ':\Users\'
            - '\.config\rclone\'
    condition: selection
falsepositives:
    - Legitimate Rclone usage
level: medium

title: Suspicious Curl File Upload - Linux
id: 00b90cc1-17ec-402c-96ad-3a8117d7a582
related:
    - id: 00bca14a-df4e-4649-9054-3f2aa676bc04
      type: derived
status: test
description: Detects a suspicious curl process start the adds a file to a web request
references:
    - https://twitter.com/d1r4c/status/1279042657508081664
    - https://medium.com/@petehouston/upload-files-with-curl-93064dcccc76
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1105/T1105.md#atomic-test-19---curl-upload-file
    - https://curl.se/docs/manpage.html
    - https://www.trendmicro.com/en_us/research/22/i/how-malicious-actors-abuse-native-linux-tools-in-their-attacks.html
author: Nasreddine Bencherchali (Nextron Systems), Cedric MAURUGEON (Update)
date: 2022-09-15
modified: 2023-05-02
tags:
    - attack.exfiltration
    - attack.command-and-control
    - attack.t1567
    - attack.t1105
logsource:
    category: process_creation
    product: linux
detection:
    selection_img:
        Image|endswith: '/curl'
    selection_cli:
        - CommandLine|contains:
              - ' --form' # Also covers the "--form-string"
              - ' --upload-file '
              - ' --data '
              - ' --data-' # For flags like: "--data-ascii", "--data-binary", "--data-raw", "--data-urlencode"
        - CommandLine|re: '\s-[FTd]\s' # We use regex to ensure a case sensitive argument detection
    filter_optional_localhost:
        CommandLine|contains:
            - '://localhost'
            - '://127.0.0.1'
    condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
    - Scripts created by developers and admins
level: medium

title: Suspicious Non-Browser Network Communication With Telegram API
id: c3dbbc9f-ef1d-470a-a90a-d343448d5875
status: test
description: Detects an a non-browser process interacting with the Telegram API which could indicate use of a covert C2
references:
    - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/small-sieve/NCSC-MAR-Small-Sieve.pdf
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-19
tags:
    - attack.command-and-control
    - attack.exfiltration
    - attack.t1102
    - attack.t1567
    - attack.t1105
logsource:
    product: windows
    category: network_connection
detection:
    selection:
        DestinationHostname|contains: 'api.telegram.org'
    # Other browsers or apps known to use telegram should be added
    # TODO: Add full paths for default install locations
    filter_main_brave:
        Image|endswith: '\brave.exe'
    filter_main_chrome:
        Image:
            - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
            - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
    filter_main_firefox:
        Image:
            - 'C:\Program Files\Mozilla Firefox\firefox.exe'
            - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
    filter_main_ie:
        Image:
            - 'C:\Program Files (x86)\Internet Explorer\iexplore.exe'
            - 'C:\Program Files\Internet Explorer\iexplore.exe'
    filter_main_maxthon:
        Image|endswith: '\maxthon.exe'
    filter_main_edge_1:
        - Image|startswith: 'C:\Program Files (x86)\Microsoft\EdgeWebView\Application\'
        - Image|endswith: '\WindowsApps\MicrosoftEdge.exe'
        - Image:
              - 'C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe'
              - 'C:\Program Files\Microsoft\Edge\Application\msedge.exe'
    filter_main_edge_2:
        Image|startswith:
            - 'C:\Program Files (x86)\Microsoft\EdgeCore\'
            - 'C:\Program Files\Microsoft\EdgeCore\'
        Image|endswith:
            - '\msedge.exe'
            - '\msedgewebview2.exe'
    filter_main_opera:
        Image|endswith: '\opera.exe'
    filter_main_safari:
        Image|endswith: '\safari.exe'
    filter_main_seamonkey:
        Image|endswith: '\seamonkey.exe'
    filter_main_vivaldi:
        Image|endswith: '\vivaldi.exe'
    filter_main_whale:
        Image|endswith: '\whale.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate applications communicating with the Telegram API e.g. web browsers not in the exclusion list, app with an RSS  etc.
level: medium

title: DNS Query To Ufile.io
id: 1cbbeaaf-3c8c-4e4c-9d72-49485b6a176b
related:
    - id: 090ffaad-c01a-4879-850c-6d57da98452d
      type: similar
status: test
description: Detects DNS queries to "ufile.io", which was seen abused by malware and threat actors as a method for data exfiltration
references:
    - https://thedfirreport.com/2021/12/13/diavol-ransomware/
author: yatinwad, TheDFIRReport
date: 2022-06-23
modified: 2023-09-18
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    category: dns_query
detection:
    selection:
        QueryName|contains: 'ufile.io'
    condition: selection
falsepositives:
    - DNS queries for "ufile" are not malicious by nature necessarily. Investigate the source to determine the necessary actions to take
level: low

title: DNS Query To Ufile.io - DNS Client
id: 090ffaad-c01a-4879-850c-6d57da98452d
related:
    - id: 1cbbeaaf-3c8c-4e4c-9d72-49485b6a176b
      type: similar
status: test
description: Detects DNS queries to "ufile.io", which was seen abused by malware and threat actors as a method for data exfiltration
references:
    - https://thedfirreport.com/2021/12/13/diavol-ransomware/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-01-16
modified: 2023-09-18
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    product: windows
    service: dns-client
    definition: 'Requirements: Microsoft-Windows-DNS Client Events/Operational Event Log must be enabled/collected in order to receive the events.'
detection:
    selection:
        EventID: 3008
        QueryName|contains: 'ufile.io'
    condition: selection
falsepositives:
    - DNS queries for "ufile" are not malicious by nature necessarily. Investigate the source to determine the necessary actions to take
level: low

title: GitHub Repository Pages Site Changed to Public
id: 0c46d4f4-a2bf-4104-9597-8d653fc2bb55
status: experimental
description: |
    Detects when a GitHub Pages site of a repository is made public. This usually is part of a publishing process but could indicate or lead to potential unauthorized exposure of sensitive information or code.
references:
    - https://docs.github.com/en/pages/getting-started-with-github-pages/creating-a-github-pages-site
    - https://www.sentinelone.com/blog/exploiting-repos-6-ways-threat-actors-abuse-github-other-devops-platforms
    - https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/security-log-events
author: Ivan Saakov
date: 2025-10-18
tags:
    - attack.collection
    - attack.exfiltration
    - attack.t1567.001
logsource:
    product: github
    service: audit
detection:
    selection:
        action: 'repo.pages_public'
    condition: selection
falsepositives:
    - Legitimate publishing of repository pages by authorized users
level: low

title: Network Connection Initiated To Mega.nz
id: fdeebdf0-9f3f-4d08-84a6-4c4d13e39fe4
status: test
description: |
    Detects a network connection initiated by a binary to "api.mega.co.nz".
    Attackers were seen abusing file sharing websites similar to "mega.nz" in order to upload/download additional payloads.
references:
    - https://megatools.megous.com/
    - https://www.mandiant.com/resources/russian-targeting-gov-business
author: Florian Roth (Nextron Systems)
date: 2021-12-06
modified: 2024-05-31
tags:
    - attack.exfiltration
    - attack.t1567.002
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        Initiated: 'true'
        DestinationHostname|endswith:
            - 'mega.co.nz'
            - 'mega.nz'
    condition: selection
falsepositives:
    - Legitimate MEGA installers and utilities are expected to communicate with this domain. Exclude hosts that are known to be allowed to use this tool.
level: low