Detection rules › Sigma

Potential Arbitrary File Download Via Cmdl32.EXE

Severity
medium
Author
frack113
Source
upstream

Detects execution of Cmdl32 with the "/vpn" and "/lan" flags. Attackers can abuse this utility in order to download arbitrary files via a configuration file. Inspect the location and the content of the file passed as an argument in order to determine if it is suspicious.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1202 Indirect Command Execution, T1218 System Binary Proxy Execution

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\cmdl32.exe'
OriginalFileName: CMDL32.EXE

Stage 2: all of selection_cli

CommandLine|contains: '/lan'
CommandLine|contains: '/vpn'

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
CommandLinematch
  • /lan
  • /vpn
Imageends_with
  • \cmdl32.exe corpus 2 (sigma 2)
OriginalFileNameeq
  • CMDL32.EXE