Suspicious Rundll32 Loading Non-DLL Image Extension File

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055.012Process Hollowing
Defense Evasion
- T1055.012Process Hollowing
- T1218.011Rundll32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects rundll32.exe executing an export from a file carrying an image or media extension rather than a DLL, a defense-evasion pattern used by APT41 PLUSDROP to conceal its loader payload. Running exported code from a masqueraded file lets the actor stage process injection into svchost.exe.

Reporting behind it

Related detections9 linkedT1218.011 — drag to rearrange

Malicious Rundll32 Execution of Image File Export via PLUSDROP

Suspicious MSBuild Execution Spawned by Command Shell for Process Hollowing (via process_creation)

Malicious DAEMON Tools Backdoor Execution via rundll32 mcrypto (via process_creation)

Suspicious rundll32 Execution of IconCache Masquerading DLL

Malicious LSASS Credential Dump via rundll32 and comsvcs MiniDump

Malicious Desktop Window Manager Impersonation From Non-System Path via process_creation

Suspicious Rundll32 Execution Without Arguments

Malicious rundll32 Execution of BoomBox NativeCache DLL (via process_creation)

Malicious rundll32 vbscript mshtml RunHTMLApplication Execution

Suspicious Rundll32 Loading Non-DLL Image Extension File

Pivot detection · T1218.011 · 9 related

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

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →