Detection rules › Sigma

Potential Persistence Via Netsh Helper DLL

Severity
medium
Author
Victor Sergeev, oscd.community
Source
upstream

Detects the execution of netsh with "add helper" flag in order to add a custom helper DLL. This technique can be abused to add a malicious helper DLL that can be used as a persistence proxy that gets called when netsh.exe is executed.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1546.007 Event Triggered Execution: Netsh Helper DLL
Privilege EscalationT1546.007 Event Triggered Execution: Netsh Helper DLL

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\netsh.exe'
OriginalFileName: netsh.exe

Stage 2: all of selection_cli

CommandLine|contains: add
CommandLine|contains: helper

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
  • add corpus 16 (sigma 16)
  • helper
Imageends_with
  • \netsh.exe corpus 16 (sigma 16)
OriginalFileNameeq
  • netsh.exe corpus 14 (sigma 14)