Use of Pcalua For Execution

Severity: medium
Author: Nasreddine Bencherchali (Nextron Systems), E.M. Anhaus (originally from Atomic Blue Detections, Endgame), oscd.community
Source: upstream

Detects execition of commands and binaries from the context of The program compatibility assistant (Pcalua.exe). This can be used as a LOLBIN in order to bypass application whitelisting.

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `selection`

CommandLine|contains: ' -a'
Image|endswith: '\pcalua.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.