Interactive Bash Suspicious Children

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

medium 2 ATT&CK techniques 3 programs it names

What it looks for

its detection, as SigmaHQ writes it

detection:
  anomaly1:
    CommandLine|contains:
      - '-c import '
      - 'base64'
      - 'pty.spawn'
  anomaly2:
    Image|endswith:
      - 'whoami'
      - 'iptables'
      - '/ncat'
      - '/nc'
      - '/netcat'
  selection:
    ParentCommandLine: 'bash -i'
  condition: selection and 1 of anomaly*

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.

Programs and files it names

their pages here

ncncatnetcat

ATT&CK

the techniques it is tagged with

T1036Masquerading

T1059.004Command and Scripting Interpreter: Unix Shell

Interactive Bash Suspicious Children

What it looks for

Programs and files it names

ATT&CK

Other rules for T1036 Masquerading