Detection rules › Sigma

Steganography Hide Zip Information in Picture File

Status
test
Severity
low
Log source
product linux, service auditd
Author
Pawel Mazur
Source
github.com/SigmaHQ/sigma

Detects appending of zip file to image

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Steganography Hide Zip Information in Picture File
id: 45810b50-7edc-42ca-813b-bdac02fb946b
status: test
description: Detects appending of zip file to image
references:
    - https://zerotoroot.me/steganography-hiding-a-zip-in-a-jpeg-file/
author: 'Pawel Mazur'
date: 2021-09-09
modified: 2022-10-09
tags:
    - attack.stealth
    - attack.t1027.003
logsource:
    product: linux
    service: auditd
detection:
    commands:
        type: EXECVE
        a0: cat
    a1:
        a1|endswith:
            - '.jpg'
            - '.png'
    a2:
        a2|endswith: '.zip'
    condition: commands and a1 and a2
falsepositives:
    - Unknown
level: low

Stages and Predicates

Stage 0: condition

commands and a1 and a2

Stage 1: commands

commands:
    type: EXECVE
    a0: cat

Stage 2: a1

a1:
    a1|endswith:
        - '.jpg'
        - '.png'

Stage 3: a2

a2:
    a2|endswith: '.zip'

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
  • cat
a1ends_with
  • .jpg
  • .png
a2ends_with
  • .zip
typeeq
  • EXECVE