Detection rules › Sigma

Disable Security Tools

Status
test
Severity
medium
Log source
product macos, category process_creation
Author
Daniil Yugoslavskiy, oscd.community
Source
github.com/SigmaHQ/sigma

Detects disabling security tools

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1685 Disable or Modify Tools

Event coverage

ProviderEventTitle
ESFexecProcess Execution (Notify)

Rule body yaml

title: Disable Security Tools
id: ff39f1a6-84ac-476f-a1af-37fcdf53d7c0
status: test
description: Detects disabling security tools
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
author: Daniil Yugoslavskiy, oscd.community
date: 2020-10-19
modified: 2021-11-27
tags:
    - attack.defense-impairment
    - attack.t1685
logsource:
    category: process_creation
    product: macos
detection:
    launchctl_unload:
        Image: '/bin/launchctl'
        CommandLine|contains: 'unload'
    security_plists:
        CommandLine|contains:
            - 'com.objective-see.lulu.plist'                     # Objective-See firewall management utility
            - 'com.objective-see.blockblock.plist'               # Objective-See persistence locations watcher/blocker
            - 'com.google.santad.plist'                          # google santa
            - 'com.carbonblack.defense.daemon.plist'             # carbon black
            - 'com.carbonblack.daemon.plist'                     # carbon black
            - 'at.obdev.littlesnitchd.plist'                     # Objective Development Software firewall management utility
            - 'com.tenablesecurity.nessusagent.plist'            # Tenable Nessus
            - 'com.opendns.osx.RoamingClientConfigUpdater.plist' # OpenDNS Umbrella
            - 'com.crowdstrike.falcond.plist'                    # Crowdstrike Falcon
            - 'com.crowdstrike.userdaemon.plist'                 # Crowdstrike Falcon
            - 'osquery'                                          # facebook osquery
            - 'filebeat'                                         # elastic log file shipper
            - 'auditbeat'                                        # elastic auditing agent/log shipper
            - 'packetbeat'                                       # elastic network logger/shipper
            - 'td-agent'                                         # fluentd log shipper
    disable_gatekeeper:
        Image: '/usr/sbin/spctl'
        CommandLine|contains: 'disable'
    condition: (launchctl_unload and security_plists) or disable_gatekeeper
falsepositives:
    - Legitimate activities
level: medium

Stages and Predicates

Stage 0: condition

(launchctl_unload and security_plists) or disable_gatekeeper

Stage 1: launchctl_unload

launchctl_unload:
    Image: '/bin/launchctl'
    CommandLine|contains: 'unload'

Stage 2: security_plists

security_plists:
    CommandLine|contains:
        - 'com.objective-see.lulu.plist'
        - 'com.objective-see.blockblock.plist'
        - 'com.google.santad.plist'
        - 'com.carbonblack.defense.daemon.plist'
        - 'com.carbonblack.daemon.plist'
        - 'at.obdev.littlesnitchd.plist'
        - 'com.tenablesecurity.nessusagent.plist'
        - 'com.opendns.osx.RoamingClientConfigUpdater.plist'
        - 'com.crowdstrike.falcond.plist'
        - 'com.crowdstrike.userdaemon.plist'
        - 'osquery'
        - 'filebeat'
        - 'auditbeat'
        - 'packetbeat'
        - 'td-agent'

Stage 3: disable_gatekeeper

disable_gatekeeper:
    Image: '/usr/sbin/spctl'
    CommandLine|contains: 'disable'

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
CommandLinematch
  • at.obdev.littlesnitchd.plist
  • auditbeat
  • com.carbonblack.daemon.plist
  • com.carbonblack.defense.daemon.plist
  • com.crowdstrike.falcond.plist
  • com.crowdstrike.userdaemon.plist
  • com.google.santad.plist
  • com.objective-see.blockblock.plist
  • com.objective-see.lulu.plist
  • com.opendns.osx.RoamingClientConfigUpdater.plist
  • com.tenablesecurity.nessusagent.plist
  • disable
  • filebeat
  • osquery
  • packetbeat
  • td-agent
  • unload
Imageeq
  • /bin/launchctl
  • /usr/sbin/spctl