Malicious AquaShell Webshell Access on Cisco Secure Email Gateway by UAT-9686

PremiumReviewedSigma · High · v1
Category
webserver
Author
HuntRule
Published
2026-09-12
Updated
2026-09-12

ATT&CK techniques

Persistence
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Priv Esc

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. C2

  12. Exfiltration

  13. Impact

What it detects

This rule detects HTTP POST requests to the AquaShell Python webshell planted at the euq_webui index.py endpoint on Cisco Secure Email appliances. UAT-9686 uses this unauthenticated webshell to execute arbitrary commands on compromised gateways. Requests to this appliance path indicate active exploitation and remote command execution.

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Malicious AquaShell Webshell Access on Cisco Secure Email Gateway by UAT-9686
Pivot detection · T1505.003 · 9 related

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