Suspicious curl Download Spawned by Excel via IQY Attachment (via process_creation)

PremiumReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-09-16
Updated
2026-09-16

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 Excel spawning a command shell that runs curl, the initial execution chain triggered by the malicious IQY attachment in the Bitter APT PTCL campaign. Office applications launching curl through cmd to fetch remote payloads is not legitimate document behavior. This parent-child chain indicates weaponized document execution.

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Pivot detection · T1204.002 · 9 related

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