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Suspicious aspnet_compiler.exe Execution from User or Temp Paths on Windows

Alerts when aspnet_compiler.exe runs with command lines indicating user-writable or temp/task paths.

FreeReviewedSigma · High · v2
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2023-08-14
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Execution → Defense Evasion

  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 process creation events where aspnet_compiler.exe is launched from common Microsoft .NET Framework directories, with command lines containing potentially suspicious path locations. Attackers may use legitimate .NET tooling to blend in with normal system activity while performing compilation or staging in writable user-controlled directories. The detection relies on Windows process creation telemetry, matching the executable path suffix and the presence of specific suspicious path strings in the command line.

Reporting behind it

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Windows: Process creation involving VSIISExeLauncher.exe with -p and -a arguments
Windows Process Creation: Mftrace.exe Child Process Execution
Windows Process Creation: Remote.exe Execution
Windows Process Creation: wfc.exe Execution for Workflow Command-line Compiler Abuse
Suspicious aspnet_compiler.exe Execution from User or Temp Paths on Windows
Pivot detection · T1127 · 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.