CmdID

CmdID / Rules / Windows

Indirect Inline Command Execution Via Bash.EXE

A Sigma rule for process creation on Windows, by frack113.

medium 1 ATT&CK technique 1 program it names 1 everyday example trips it

What it looks for

its detection, as SigmaHQ writes it
detection:
  selection_cli:
    CommandLine|contains: ' -c '
  selection_img:
    - Image|endswith:
        - ':\Windows\System32\bash.exe'
        - ':\Windows\SysWOW64\bash.exe'
    - OriginalFileName: 'Bash.exe'
  condition: all of 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 frack113, 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

everyday examples from tldr-pages, CC BY 4.0, each read by CmdID

Execute specific commands on the page for bash.exe

bash -c "echo 'bash is executed'"Identify

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

Programs and files it names

their pages here
bash.exe

ATT&CK

the techniques it is tagged with
T1202Indirect Command Execution

Other rules for T1202 Indirect Command Execution

Indirect Command Execution From Script File Via Bash.EXE · Potential Arbitrary File Download Via Cmdl32.EXE · Suspicious High IntegrityLevel Conhost Legacy Option · Uncommon Child Process Of Conhost.EXE · Potentially Suspicious Child Processes Spawned by ConHost · Suspicious ZipExec Execution · Potential Arbitrary Command Execution Using Msdt.EXE · Suspicious Cabinet File Execution Via Msdt.EXE · Potential Arbitrary File Download Using Office Application · Potentially Suspicious Office Document Executed From Trusted Location · Potential Arbitrary DLL Load Using Winword · Renamed PAExec Execution