Uncommon Child Process Of Setres.EXE

Status: test
Severity: high
Log source: category process_creation, product windows
Author: @gott_cyber, Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

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.

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1202` Indirect Command Execution `T1218` System Binary Proxy Execution

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Uncommon Child Process Of Setres.EXE
id: 835e75bf-4bfd-47a4-b8a6-b766cac8bcb7
status: test
description: |
    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.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Setres/
    - https://twitter.com/0gtweet/status/1583356502340870144
    - https://strontic.github.io/xcyclopedia/library/setres.exe-0E30E4C09637D7A128A37B59A3BC4D09.html
    - https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731033(v=ws.11)
author: '@gott_cyber, Nasreddine Bencherchali (Nextron Systems)'
date: 2022-12-11
modified: 2024-06-26
tags:
    - attack.stealth
    - attack.t1218
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\setres.exe'
        Image|contains: '\choice'
    filter_main_legit_location:
        Image|endswith:
            - 'C:\Windows\System32\choice.exe'
            - 'C:\Windows\SysWOW64\choice.exe'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_*

Stage 1: `selection`

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

Stage 2: `not filter_main_legit_location`

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

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	ends_with	`C:\Windows\SysWOW64\choice.exe`	`excludes:Image` `field:"Image" value:"C:\Windows\SysWOW64\choice.exe"`
`Image`	ends_with	`C:\Windows\System32\choice.exe`	`excludes:Image` `field:"Image" value:"C:\Windows\System32\choice.exe"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	match	`\choice`	`field:"Image" kind:match value:"\choice"`
`ParentImage`	ends_with	`\setres.exe`	`field:"ParentImage" kind:ends_with value:"\setres.exe"`