huntrule

Suspicious Notepad Access to Active Directory Enumeration Output Files

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-10-01
Updated
2026-10-01
AnalysisDetection

ATT&CK techniques

Discovery

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule detects notepad.exe opening files named AdUsers.txt or AdComp.txt, matching hands-on-keyboard review of Active Directory enumeration output observed in Akira ransomware intrusions. Operators dump domain user and computer lists to text files and open them in Notepad while scoping the environment before encryption. This reconnaissance review precedes lateral movement and mass data destruction.

Reporting behind it

Related detections9 linkedT1087.002 — drag to rearrange
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Suspicious LDAP Security Descriptor Enumeration via SD_FLAGS Control
Suspicious LDAP Query Enumerating Kerberos Preauth Disabled Accounts with Whitespace Evasion
Suspicious Delegation Discovery LDAP Search Filter via Bitwise OID
Suspicious PowerShell Execution of Untitled1 Script From ProgramData
Suspicious Service Principal Name Discovery via setspn Query
Suspicious Domain Admins Enumeration via Net Group
Suspicious Notepad Access to Active Directory Enumeration Output Files
Pivot detection · T1087.002 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.