Suspicious mshta Execution Proxied Through pcalua LOLBIN

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218.005Mshta
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the Program Compatibility Assistant (pcalua.exe) launching mshta.exe, matching the ClickFix execution chain of the Potemkin loader and RMMProject campaign. Adversaries abuse pcalua as a signed proxy to spawn mshta and run remote HTA or script payloads while evading parent-child heuristics. This chain initiates loader delivery and follow-on remote access tooling.

Reporting behind it

Related detections9 linkedT1218.005 — drag to rearrange

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Suspicious Remote HTA Execution via mshta over HTTP

Suspicious Remote HTA Execution via mshta from File Sharing Site

Suspicious Copy of System mshta.exe into ProgramData by SideWinder APT

Malicious Renamed mshta.exe Execution by SideWinder APT

Suspicious MSHTA Execution Spawned by Browser or Document Reader via Mispadu (via process_creation)

Suspicious Office Application Spawning Mshta With Remote HTA

Suspicious MSHTA VBScript WScript Shell Execution

Suspicious mshta Execution Proxied Through pcalua LOLBIN

Pivot detection · T1218.005 · 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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