Detection rules › Sigma

Masquerading as Linux Crond Process

Status
test
Severity
medium
Log source
product linux, service auditd
Author
Timur Zinniatullin, oscd.community
Source
github.com/SigmaHQ/sigma

Masquerading occurs when the name or location of an executable, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. Several different variations of this technique have been observed.

MITRE ATT&CK coverage

Rule body yaml

title: Masquerading as Linux Crond Process
id: 9d4548fa-bba0-4e88-bd66-5d5bf516cda0
status: test
description: |
  Masquerading occurs when the name or location of an executable, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation.
  Several different variations of this technique have been observed.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/8a82e9b66a5b4f4bc5b91089e9f24e0544f20ad7/atomics/T1036.003/T1036.003.md#atomic-test-2---masquerading-as-linux-crond-process
author: Timur Zinniatullin, oscd.community
date: 2019-10-21
modified: 2023-08-22
tags:
    - attack.stealth
    - attack.t1036.003
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: 'execve'
        a0: 'cp'
        a1: '/bin/sh'
        a2|endswith: '/crond'
    condition: selection
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    type: 'execve'
    a0: 'cp'
    a1: '/bin/sh'
    a2|endswith: '/crond'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
a0eq
  • cp
a1eq
  • /bin/sh
a2ends_with
  • /crond
typeeq
  • execve