JXA In-memory Execution Via OSAScript

A Sigma rule for process creation on macOS, by Sohan G (D4rkCiph3r).

high 2 ATT&CK techniques

What it looks for

its detection, as SigmaHQ writes it

detection:
  selection_js:
    - CommandLine|contains|all:
        - ' -l '
        - 'JavaScript'
    - CommandLine|contains: '.js'
  selection_main:
    CommandLine|contains|all:
      - 'osascript'
      - ' -e '
      - 'eval'
      - 'NSData.dataWithContentsOfURL'
  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 Sohan G (D4rkCiph3r), 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

T1059.002Command and Scripting Interpreter: AppleScript

T1059.007Command and Scripting Interpreter: JavaScript

JXA In-memory Execution Via OSAScript

What it looks for

ATT&CK

Other rules for T1059.002 Command and Scripting Interpreter: AppleScript