Suspicious Download and Execute Pattern via Curl/Wget

A Sigma rule for process creation on Linux, by Aayush Gupta.

high 2 ATT&CK techniques

What it looks for

its detection, as SigmaHQ writes it

detection:
  selection_downloader:
    CommandLine|contains:
      - '/curl'
      - '/wget'
  selection_executor:
    CommandLine|contains: 'sh -c'
  selection_tmp:
    CommandLine|contains:
      - '/tmp/'
      - '/dev/shm/'
  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 Aayush Gupta, 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

T1059.004Command and Scripting Interpreter: Unix Shell

T1203Exploitation for Client Execution

Suspicious Download and Execute Pattern via Curl/Wget

What it looks for

ATT&CK

Other rules for T1059.004 Command and Scripting Interpreter: Unix Shell