Suspicious Download to Windows appcompat Directory via PowerShell

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-06-18
Updated
2026-08-28

ATT&CK techniques

Execution → C2
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Persistence

  5. Priv Esc

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. Exfiltration

  12. Impact

What it detects

This rule detects PowerShell using Invoke-WebRequest to write an executable into the Windows appcompat directory as observed after Triofox CVE-2025-12480 exploitation. Attackers stage payloads such as SAgentInstaller.exe in unusual system paths to evade attention.

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Suspicious Download to Windows appcompat Directory via PowerShell
Pivot detection · T1059.001 · 9 related

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