Rundll32.exe running with no command-line arguments

Cortex XDR Analytics Alert Reference by Alert name

Product
Cortex XDR
Last date published
2024-06-04
Category
Analytics Alert Reference
Order
Alert name

Synopsis

Activation Period

14 Days

Training Period

30 Days

Test Period

N/A (single event)

Deduplication Period

1 Day

Required Data

  • Requires:
    • XDR Agent

Detection Modules

ATT&CK Tactic

Defense Evasion (TA0005)

ATT&CK Technique

System Binary Proxy Execution: Rundll32 (T1218.011)

Severity

Medium

Description

Rundll32.exe is meant to run with parameters, so the absence of them is extremely suspicious; this behavior is used in the default configuration of Cobalt Strike.

Attacker's Goals

  • Run as a signed Microsoft executables to avoid detection.
  • Rundll32 is the default process used by Cobalt Strike for running post-exploitation tools.

Investigative actions

  • Check for any injection event to the Rundll32 process.
  • Check the causality of execution for any injections.