Detection rules › Sigma

Setup16.EXE Execution With Custom .Lst File

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
frack113
Source
github.com/SigmaHQ/sigma

Detects the execution of "Setup16.EXE" and old installation utility with a custom ".lst" file. These ".lst" file can contain references to external program that "Setup16.EXE" will execute. Attackers and adversaries might leverage this as a living of the land utility.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Setup16.EXE Execution With Custom .Lst File
id: 99c8be4f-3087-4f9f-9c24-8c7e257b442e
status: test
description: |
    Detects the execution of "Setup16.EXE" and old installation utility with a custom ".lst" file.
    These ".lst" file can contain references to external program that "Setup16.EXE" will execute.
    Attackers and adversaries might leverage this as a living of the land utility.
references:
    - https://www.hexacorn.com/blog/2024/10/12/the-sweet16-the-oldbin-lolbin-called-setup16-exe/
author: frack113
date: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.execution
    - attack.stealth
    - attack.t1574.005
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage: 'C:\Windows\SysWOW64\setup16.exe'
        ParentCommandLine|contains: ' -m '
    filter_optional_valid_path:
        Image|startswith: 'C:\~MSSETUP.T\'
    condition: selection and not 1 of filter_optional_*
falsepositives:
    - On modern Windows system, the "Setup16" utility is practically never used, hence false positive should be very rare.
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_optional_*

Stage 1: selection

selection:
    ParentImage: 'C:\Windows\SysWOW64\setup16.exe'
    ParentCommandLine|contains: ' -m '

Stage 2: not filter_optional_valid_path

filter_optional_valid_path:
    Image|startswith: 'C:\~MSSETUP.T\'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imagestarts_withC:\~MSSETUP.T\

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.

FieldKindValues
ParentCommandLinematch
  • -m
ParentImageeq
  • C:\Windows\SysWOW64\setup16.exe