Query: detect Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privile in logs
Matching passage: Sigma rule: Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privile. Logsource: linux / auditd. Rule: title: Potential Abuse of Linux Magic System Request Key id: ea61bb82-a5e0-42e6-8537-91d29500f1b9 status: experimental description: 'Detects the potential abuse of the Linux Magic SysRq (System Request) key by adversaries with root or sufficient privileges to silently manipulate or destabilize a system. By writing to /proc/sysrq-trigger, they can crash the system, kill processes, or disrupt forensic analysis—all while bypassing standard logging. Though intended for recovery and debugging, SysRq can be misused as a stealthy post-exploitation tool. It is controlled via /proc/sys/kernel/sysrq or permanently through /etc/sysctl.conf. ' references: - https://www.kernel.org/doc/html/v4.10/_sources/admin-guide/sysrq.txt - https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/4/html/reference_guide/s3-proc-sys-kernel - https://www.splunk.com/en_us/blog/security/threat-update-awfulshred-script-wiper.html author: Milad Cheraghi date: 2025-05-23 tags: - attack.execution - attack.t1059.004 - attack.impact - attack.t1529 - attack.t1489 - attack.t1499 logsource: product: linux service: auditd definition: 'Required auditd configuration: -w /proc/sysrq-trigger -p wa -k sysrq -w /proc/sys/kernel/sysrq -p wa -k sysrq ' detection: selection: type: PATH name|endswith: - /sysrq - /sysctl.conf - /sysrq-trigger condition: selection falsepositives: - Legitimate administrative activity level: medium
Near-miss passage: Sigma rule: Detects attempts to disable AMSI (Anti-Malware Scan Interface) by modifying the AmsiEnable registry value. Anti-Malware. Logsource: windows / registry_set. Rule: title: AMSI Disabled via Registry Modification id: aa37cbb0-da36-42cb-a90f-fdf216fc7467 related: - id: 7dbbcac2-57a0-45ac-b306-ff30a8bd2981 type: similar status: experimental description: 'Detects attempts to disable AMSI (Anti-Malware Scan Interface) by modifying the AmsiEnable registry value. Anti-Malware Scan Interface (AMSI) is a security feature in Windows that allows applications and services to integrate with anti-malware products for enhanced protection against malicious content. Adversaries may attempt to disable AMSI to evade detection by security software, allowing them to execute malicious scripts or code without being scanned. ' references: - https://mostafayahiax.medium.com/hunting-for-amsi-bypassing-methods-9886dda0bf9d - https://docs.microsoft.com/en-us/windows/win32/amsi/antimalware-scan-interface-portal - https://www.mdsec.co.uk/2019/02/macros-and-more-with-sharpshooter-v2-0/ author: Swachchhanda Shrawan Poudel (Nextron Systems) date: 2025-12-25 tags: - attack.defense-impairment - attack.t1685 logsource: category: registry_set product: windows detection: selection: TargetObject|endswith: \Software\Microsoft\Windows Script\Settings\AmsiEnable Details: DWORD (0x00000000) condition: selection falsepositives: - Unlikely level: high regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_amsi_disable/info.yml simulation: - type: atomic-red-team name: AMSI Bypass - Create AMSIEnable Reg Key technique: T1562.001 atomic_guid: 728eca7b-0444-4f6f-ac36-437e3d751dc0