Detection rules › Sigma

NtdllPipe Like Activity Execution

Severity
high
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects command that type the content of ntdll.dll to a different file or a pipe in order to evade AV / EDR detection. As seen being used in the POC NtdllPipe

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.

Stages and Predicates

Stage 1: selection

or:
CommandLine|contains: '\\ntdll.dll > \\\\.\\pipe\\'
CommandLine|contains: 'type %systemroot%\system32\ntdll.dll'
CommandLine|contains: 'type %windir%\system32\ntdll.dll'
CommandLine|contains: 'type c:\windows\system32\ntdll.dll'

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
  • \\ntdll.dll > \\\\.\\pipe\\
  • type %systemroot%\system32\ntdll.dll
  • type %windir%\system32\ntdll.dll
  • type c:\windows\system32\ntdll.dll