huntrule

Windows: Command-line contains long ab-prefixed string seen in TropicTrooper activity (Nov 2018)

Detects Windows processes whose command line contains a known TropicTrooper campaign indicator string.

FreeReviewedSigma · High · v5
Product
windows
Category
process_creation
Author
@41thexplorer, Microsoft Defender ATP (SigmaHQ), DRL 1.1
Published
2019-11-12
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution

  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 matches Windows process creation events where the command line contains a specific long string beginning with "ab". Such exact command-line patterns can indicate scripted or staged execution used during targeted intrusions. The detection relies on process creation telemetry with access to the full command line.

Reporting behind it

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Malicious PowerShell Spawned by Masqueraded NVIDIA GeForce Experience Binary
Suspicious PowerShell Hidden Unrestricted Execution via ClickFix
Suspicious PowerShell Spawned by cscript in Script Chain
Windows: Command-line contains long ab-prefixed string seen in TropicTrooper activity (Nov 2018)
Pivot detection · T1059.001 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. 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.