PUA - Wsudo Suspicious Execution

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects usage of wsudo (Windows Sudo Utility). Which is a tool that let the user execute programs with different permissions (System, Trusted Installer, Administrator...etc)

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059` Command and Scripting Interpreter

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `1 of selection_metadata`

or:
Description: 'Windows sudo utility'
Image|endswith: '\wsudo.exe'
OriginalFileName: wsudo.exe
ParentImage|endswith: '\wsudo-bridge.exe'

Stage 2: `1 of selection_cli`

or:
CommandLine|contains: ' --ti '
CommandLine|contains: '-u System'
CommandLine|contains: '-u TrustedInstaller'
CommandLine|contains: -uSystem
CommandLine|contains: -uTrustedInstaller

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.

Field	Kind	Values
`CommandLine`	match	`--ti` `-u System` `-u TrustedInstaller` `-uSystem` `-uTrustedInstaller`
`Description`	eq	`Windows sudo utility`
`Image`	ends_with	`\wsudo.exe`
`OriginalFileName`	eq	`wsudo.exe`
`ParentImage`	ends_with	`\wsudo-bridge.exe`