CAR-2014-11-002.yaml

---
title: Outlier Parents of Cmd
submission_date: 2014/11/06
information_domain: Host
platforms:
  - Windows
subtypes:
  - Process
analytic_types:
  - Anomaly
  - TTP
contributors:
  - MITRE
id: CAR-2014-11-002
description: |
  Many programs create command prompts as part of their normal operation including malware used by attackers. This analytic attempts to identify suspicious programs spawning `cmd.exe` by looking for programs that do not normally create `cmd.exe`.

  While this analytic does not take the user into account, doing so could generate further interesting results.
  It is very common for some programs to spawn cmd.exe as a subprocess, for example to run batch files or windows commands. However many process don’t routinely launch a command prompt – for example Microsoft Outlook. A command prompt being launched from a process that normally doesn’t launch command prompts could be the result of malicious code being injected into that process, or of an attacker replacing a legitimate program with a malicious one.


  ### Output Description

  The time and host the new process was started as well as its parent

coverage:
  - technique: T1059
    tactics:
      - TA0002
    subtechniques:
      - T1059.003
    coverage: Moderate
implementations:
  - description: 'Create a baseline of parents of `cmd.exe` seen over the last 30 days and a list of parents of `cmd.exe` seen today. Remove parents in the baseline from parents seen today, leaving a list of new parents.'
    code: |
      processes = search Process:Create
      cmd = filter processes where (exe == "cmd.exe")
      cmd = from cmd select parent_exe
      historic_cmd = filter cmd (where timestamp < now - 1 day AND timestamp > now - 1 day)
      current_cmd = filter cmd (where timestamp >= now - 1 day)
      new_cmd = historic_cmd - current_cmd
      output new_cmd
    type: pseudocode
data_model_references:
  - process/create/exe
  - process/create/parent_exe
d3fend_mappings:
  - iri: d3f:ProcessLineageAnalysis
    id: D3-PLA
    label: Process Lineage Analysis