Detection rules › Sigma

Disable Or Stop Services

Status
test
Severity
medium
Log source
category process_creation, product linux
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the usage of utilities such as 'systemctl', 'service'...etc to stop or disable tools and services on Linux systems. Attackers may stop or disable security tools and services to evade detection, maintain persistence, or disrupt system operations.

Known false positives

  • Legitimate administration activities
  • Some false positives are to be expected. Apply additional filters as needed before pushing to production.

MITRE ATT&CK coverage

TacticTechniques
Defense Impairment
Impact

Telemetry coverage

PlatformRecord / event type
LinuxEvent ID 1: Process Create

Rule body

title: Disable Or Stop Services
id: de25eeb8-3655-4643-ac3a-b662d3f26b6b
status: test
description: |
    Detects the usage of utilities such as 'systemctl', 'service'...etc to stop or disable tools and services on Linux systems.
    Attackers may stop or disable security tools and services to evade detection, maintain persistence, or disrupt system operations.
references:
    - https://www.trendmicro.com/pl_pl/research/20/i/the-evolution-of-malicious-shell-scripts.html
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-15
modified: 2025-03-18
tags:
    - attack.defense-impairment
    - attack.t1685
    - attack.impact
    - attack.t1489
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith:
            - '/service'
            - '/systemctl'
            - '/chkconfig'
        CommandLine|contains:
            - ' stop '
            - ' disable '
    filter_main_legit_snapd:
        Image|endswith: '/systemctl'
        CommandLine|contains:
            - '--no-reload disable snap-snapd-'
            - ' stop snap-snapd-'
    filter_main_ssh_preinstall:
        Image|endswith: '/systemctl'
        ParentCommandLine|contains: 'tmp.ci/preinst upgrade'
        CommandLine|contains|all:
            - ' stop '
            - 'ssh.'
    filter_main_ubuntu_upgrade:
        ParentCommandLine|contains: '/dpkg/info/ubuntu-pro-client.prerm upgrade'
        Image|endswith: '/systemctl'
    filter_optional_aws_agent:
        Image|endswith: '/systemctl'
        CommandLine|endswith: 'snap.amazon-ssm-agent.amazon-ssm-agent.service'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate administration activities
    - Some false positives are to be expected. Apply additional filters as needed before pushing to production.
level: medium

Stages and Predicates

Stage 0: condition

selection and not 1 of filter_main_* and not 1 of filter_optional_*

Stage 1: selection

selection:
    Image|endswith:
        - '/service'
        - '/systemctl'
        - '/chkconfig'
    CommandLine|contains:
        - ' stop '
        - ' disable '

Stage 2: not filter_main_*

filter_main_legit_snapd:
    Image|endswith: '/systemctl'
    CommandLine|contains:
        - '--no-reload disable snap-snapd-'
        - ' stop snap-snapd-'
filter_main_ssh_preinstall:
    Image|endswith: '/systemctl'
    ParentCommandLine|contains: 'tmp.ci/preinst upgrade'
    CommandLine|contains|all:
        - ' stop '
        - 'ssh.'
filter_main_ubuntu_upgrade:
    ParentCommandLine|contains: '/dpkg/info/ubuntu-pro-client.prerm upgrade'
    Image|endswith: '/systemctl'

Stage 3: not filter_optional_aws_agent

filter_optional_aws_agent:
    Image|endswith: '/systemctl'
    CommandLine|endswith: 'snap.amazon-ssm-agent.amazon-ssm-agent.service'

Exclusions

The rule actively suppresses these predicates.

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • disable
  • stop
field:"CommandLine" kind:match
Imageends_with
  • /chkconfig
  • /service
  • /systemctl
field:"Image" kind:ends_with