UAC Bypass Abusing Winsat Path Parsing - Process

Severity: high
Author: Christian Burkard (Nextron Systems)
Source: upstream

Detects the pattern of UAC Bypass using a path parsing issue in winsat.exe (UACMe 52)

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1548.002` Abuse Elevation Control Mechanism: Bypass User Account Control
Defense Evasion	`T1548.002` Abuse Elevation Control Mechanism: Bypass User Account Control

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `selection`

IntegrityLevel: [High, S-1-16-12288, S-1-16-16384, System]
ParentCommandLine|contains: 'C:\Windows \system32\winsat.exe'
ParentImage|endswith: '\AppData\Local\Temp\system32\winsat.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.