huntrule

Suspicious Curl Download Spawned by PowerShell

PremiumReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-09-29
Updated
2026-09-29
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 detects the curl client spawned as a child of PowerShell, an anomalous chain used to fetch second-stage tooling after an initial PowerShell foothold. Legitimate curl usage is rarely launched by an interactive PowerShell session. This process lineage indicates scripted download activity during post-exploitation.

Reporting behind it

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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.