UAC Bypass Abusing Winsat Path Parsing - Registry

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	13	RegistryEvent (Value Set)

Stages and Predicates

Stage 1: `selection`

Details|endswith: '\appdata\local\temp\system32\winsat.exe'
Details|startswith: 'c:\users\'
TargetObject|endswith: '\LowerCaseLongPath'
TargetObject|contains: '\Root\InventoryApplicationFile\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.