CmdID / Rules / Windows

Mshtml.DLL RunHTMLApplication Suspicious Usage

A Sigma rule for process creation on Windows, by Nasreddine Bencherchali (Nextron Systems), Florian Roth (Nextron Systems), Josh Nickels, frack113, Zaw Min Htun (ZETA).

high

What it looks for

its detection, as SigmaHQ writes it

detection:
  selection:
    CommandLine|contains:
      - '#135'
      - 'RunHTMLApplication'
    CommandLine|contains|all:
      - '\..\'
      - 'mshtml'
  condition: selection

The rule’s detection, its selections and fields in order of name. The whole rule, with its references and false positives, is on SigmaHQ, by Nasreddine Bencherchali (Nextron Systems), Florian Roth (Nextron Systems), Josh Nickels, frack113, Zaw Min Htun (ZETA), under the Detection Rule License 1.1. CmdID evaluates it on a command line alone: a test on what a command line cannot show, such as the parent process or the user, is not met.

Command lines that trip it

documented abuse, read by CmdID

The commands LOLBAS or GTFOBins documents for rundll32.exe trip it: each is on its program’s page, read by CmdID.