Query: Sigma YAML for windows / registry_event
Matching passage: Sigma rule: Detects modifications or creations of Windows Defender's default threat action settings based on severity to 'allow' or. Logsource: windows / registry_event. Rule: title: Windows Defender Threat Severity Default Action Modified id: 5a9e1b2c-8f7d-4a1e-9b3c-0f6d7e5a4b1f related: - id: 1e8a9b4d-3c2a-4f9b-8d1e-7c6a5b4f3d2e type: similar status: experimental description: 'Detects modifications or creations of Windows Defender''s default threat action settings based on severity to ''allow'' or take ''no action''. This is a highly suspicious configuration change that effectively disables Defender''s ability to automatically mitigate threats of a certain severity level, allowing malicious software to run unimpeded. An attacker might use this technique to bypass defenses before executing payloads. ' references: - https://learn.microsoft.com/en-us/powershell/module/defender/set-mppreference - https://learn.microsoft.com/en-us/windows-hardware/customize/desktop/unattend/security-malware-windows-defender-threatseveritydefaultaction - https://research.splunk.com/endpoint/7215831c-8252-4ae3-8d43-db588e82f952 - https://gist.github.com/Dump-GUY/8daef859f382b895ac6fd0cf094555d2 - https://thedfirreport.com/2021/10/18/icedid-to-xinglocker-ransomware-in-24-hours/ author: Matt Anderson (Huntress) date: 2025-07-11 tags: - attack.defense-impairment - attack.t1685 logsource: category: registry_event product: windows detection: selection: TargetObject|contains: \Microsoft\Windows Defender\Threats\ThreatSeverityDefaultAction\ TargetObject|endswith: - \1 - \2 - \4 - \5 Details: - DWORD (0x00000006) - DWORD (0x00000009) condition: selection falsepositives: - Legitimate administration via scripts or tools (e.g., SCCM, Intune, GPO enforcement). Correlate with administrative activity. - Software installations that legitimately modify Defender settings (less common for these specific keys). level: high
Near-miss passage: Sigma rule: Detects commands that try to clear or tamper with the Linux command history. This technique is used by threat actors in. Logsource: linux. Rule: title: Linux Command History Tampering id: fdc88d25-96fb-4b7c-9633-c0e417fdbd4e status: test description: 'Detects commands that try to clear or tamper with the Linux command history. This technique is used by threat actors in order to evade defenses and execute commands without them being recorded in files such as "bash_history" or "zsh_history". ' references: - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.003/T1070.003.md - https://www.hackers-arise.com/post/2016/06/20/covering-your-bash-shell-tracks-antiforensics - https://www.cadosecurity.com/spinning-yarn-a-new-linux-malware-campaign-targets-docker-apache-hadoop-redis-and-confluence/ author: Patrick Bareiss date: 2019-03-24 modified: 2024-04-17 tags: - attack.stealth - attack.t1070.003 logsource: product: linux detection: keywords: - cat /dev/null >*sh_history - cat /dev/zero >*sh_history - chattr +i*sh_history - echo "" >*sh_history - empty_bash_history - export HISTFILESIZE=0 - history -c - history -w - ln -sf /dev/null *sh_history - ln -sf /dev/zero *sh_history - rm *sh_history - shopt -ou history - shopt -uo history - shred *sh_history - truncate -s0 *sh_history condition: keywords falsepositives: - Unknown level: high