huntrule

Windows Impacket-Pattern File Creation: sessionresume_[a-zA-Z]{8} Indicator

Flags Windows file creations of filenames matching Impacket sessionresume pattern ('sessionresume_<8 letters>').

FreeReviewedSigma · High · v2
Product
windows
Category
file_event
Author
The DFIR Report, IrishDeath (SigmaHQ), DRL 1.1
Published
2025-05-19
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Cred Access

  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 flags Windows file creation events where the target filename matches a specific Impacket-related pattern: sessionresume_[a-zA-Z]{8}. Such files can be used as artifacts during credential access and other post-compromise activity, making them useful indicators of automated tooling. It relies on Windows file event telemetry that includes the created target filename and supports regex-based matching on the name.

Reporting behind it

Related detections9 linkedT1003.001 — drag to rearrange
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Malicious Credential Dumping via Mimikatz Sekurlsa Command
Malicious Mimikatz Sekurlsa Logonpasswords Credential Dump
Malicious LSASS Credential Dump via ProcDump (via process_creation)
Malicious LSASS Memory Dump via comsvcs.dll by Salt Typhoon
Malicious LSASS Dump via Process Access (via process_access)
Malicious LSASS Credential Dump with LSASSY - Process (via process_creation)
Malicious LSASS Credential Dump with LSASSY - Admin Share (via security)
Malicious Task Manager Used for LSASS Dump - Kernel (via security)
Windows Impacket-Pattern File Creation: sessionresume_[a-zA-Z]{8} Indicator
Pivot detection · T1003.001 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

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