Malicious IIS Worker Process Spawning Shell for Out-of-Band Interaction via Command Line

ATT&CK techniques

Initial Access

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the IIS worker process w3wp.exe spawning a command shell that performs a DNS lookup to an oastify out-of-band domain, an indicator of web exploitation callbacks. This was seen exploiting the WS_FTP vulnerability CVE-2023-40044 to confirm code execution. Detecting the chain exposes active server-side exploitation.

Reporting behind it

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Malicious IIS Worker Process Spawning Shell for Out-of-Band Interaction via Command Line

Pivot detection · T1190 · 9 related

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

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