Uncommon Child Process Of Setres.EXE

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

Detects uncommon child process of Setres.EXE. Setres.EXE is a Windows server only process and tool that can be used to set the screen resolution. It can potentially be abused in order to launch any arbitrary file with a name containing the word "choice" from the current execution path.

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1202` Indirect Command Execution, `T1218` System Binary Proxy Execution

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`

Image|contains: '\choice'
ParentImage|endswith: '\setres.exe'

Stage 2: `not 1 of filter_main_legit_location`

or:
Image|endswith: 'C:\Windows\SysWOW64\choice.exe'
Image|endswith: 'C:\Windows\System32\choice.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.

Field	Kind	Values
`Image`	ends_with	`C:\Windows\SysWOW64\choice.exe` `C:\Windows\System32\choice.exe`
`Image`	match	`\choice`
`ParentImage`	ends_with	`\setres.exe`