Detection rules › Sigma

Data Exfiltration with Wget

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

Detects attempts to post the file with the usage of wget utility. The adversary can bypass the permission restriction with the misconfigured sudo permission for wget utility which could allow them to read files like /etc/shadow.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Data Exfiltration with Wget
id: cb39d16b-b3b6-4a7a-8222-1cf24b686ffc
status: test
description: |
    Detects attempts to post the file with the usage of wget utility.
    The adversary can bypass the permission restriction with the misconfigured sudo permission for wget utility which could allow them to read files like /etc/shadow.
references:
    - https://linux.die.net/man/1/wget
    - https://gtfobins.github.io/gtfobins/wget/
author: 'Pawel Mazur'
date: 2021-11-18
modified: 2022-12-25
tags:
    - attack.exfiltration
    - attack.t1048.003
logsource:
    product: linux
    service: auditd
detection:
    selection:
        type: EXECVE
        a0: wget
        a1|startswith: '--post-file='
    condition: selection
falsepositives:
    - Legitimate usage of wget utility to post a file
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    type: EXECVE
    a0: wget
    a1|startswith: '--post-file='

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
  • wget
a1starts_with
  • --post-file=
typeeq
  • EXECVE