CmdID

CmdID / Rules / Windows

Process Access via TrolleyExpress Exclusion

A Sigma rule for process creation on Windows, by Florian Roth (Nextron Systems).

high 2 ATT&CK techniques

What it looks for

its detection, as SigmaHQ writes it
detection:
  filter_empty:
    OriginalFileName: null
  filter_renamed:
    OriginalFileName|contains: 'CtxInstall'
  renamed:
    Image|endswith: '\TrolleyExpress.exe'
  selection:
    CommandLine|contains:
      - '\TrolleyExpress 7'
      - '\TrolleyExpress 8'
      - '\TrolleyExpress 9'
      - '\TrolleyExpress.exe 7'
      - '\TrolleyExpress.exe 8'
      - '\TrolleyExpress.exe 9'
      - '\TrolleyExpress.exe -ma '
  condition: selection or ( renamed and not 1 of filter* )

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 Florian Roth (Nextron Systems), 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.

None of the everyday examples and documented commands on CmdID’s program pages trips it. To see whether a command line does, paste it into CmdID.

ATT&CK

the techniques it is tagged with
T1003.001OS Credential Dumping: LSASS Memory
T1218.011System Binary Proxy Execution: Rundll32