title: Audit CVE Event
id: 48d91a3a-2363-43ba-a456-ca71ac3da5c2
status: test
description: |
    Detects events generated by user-mode applications when they call the CveEventWrite API when a known vulnerability is trying to be exploited.
    MS started using this log in Jan. 2020 with CVE-2020-0601 (a Windows CryptoAPI vulnerability.
    Unfortunately, that is about the only instance of CVEs being written to this log.
references:
    - https://twitter.com/VM_vivisector/status/1217190929330655232
    - https://twitter.com/DidierStevens/status/1217533958096924676
    - https://twitter.com/FlemmingRiis/status/1217147415482060800
    - https://www.youtube.com/watch?v=ebmW42YYveI # "CVEs in Windows Event Logs? What You Need to Know" by 13Cubed.
    - https://nullsec.us/windows-event-log-audit-cve/
author: Florian Roth (Nextron Systems), Zach Mathis
date: 2020-01-15
modified: 2022-10-22
tags:
    - attack.execution
    - attack.stealth
    - attack.t1203
    - attack.privilege-escalation
    - attack.t1068
    - attack.t1211
    - attack.credential-access
    - attack.t1212
    - attack.lateral-movement
    - attack.t1210
    - attack.impact
    - attack.t1499.004
logsource:
    product: windows
    service: application
detection:
    selection:
        Provider_Name:
            - 'Microsoft-Windows-Audit-CVE'
            - 'Audit-CVE'
        EventID: 1
    condition: selection
falsepositives:
    - Unknown
level: critical

title: Apache Segmentation Fault
id: 1da8ce0b-855d-4004-8860-7d64d42063b1
status: test
description: Detects a segmentation fault error message caused by a crashing apache worker process
references:
    - http://www.securityfocus.com/infocus/1633
author: Florian Roth (Nextron Systems)
date: 2017-02-28
modified: 2021-11-27
tags:
    - attack.impact
    - attack.t1499.004
logsource:
    service: apache
    definition: 'Requirements: Must be able to collect the error.log file'
detection:
    keywords:
        - 'exit signal Segmentation Fault'
    condition: keywords
falsepositives:
    - Unknown
level: high

title: NTFS Vulnerability Exploitation
id: f14719ce-d3ab-4e25-9ce6-2899092260b0
status: test
description: This the exploitation of a NTFS vulnerability as reported without many details via Twitter
references:
    - https://twitter.com/jonasLyk/status/1347900440000811010
    - https://twitter.com/wdormann/status/1347958161609809921
    - https://www.bleepingcomputer.com/news/security/windows-10-bug-corrupts-your-hard-drive-on-seeing-this-files-icon/
author: Florian Roth (Nextron Systems)
date: 2021-01-11
modified: 2022-12-25
tags:
    - attack.impact
    - attack.t1499.001
logsource:
    product: windows
    service: system
detection:
    selection:
        Provider_Name: Ntfs
        EventID: 55
        Origin: 'File System Driver'
        Description|contains|all:
            - 'contains a corrupted file record'
            - 'The name of the file is "\"'
    condition: selection
falsepositives:
    - Unlikely
level: high

title: Nginx Core Dump
id: 59ec40bb-322e-40ab-808d-84fa690d7e56
status: test
description: Detects a core dump of a crashing Nginx worker process, which could be a signal of a serious problem or exploitation attempts.
references:
    - https://docs.nginx.com/nginx/admin-guide/monitoring/debugging/#enabling-core-dumps
    - https://www.x41-dsec.de/lab/advisories/x41-2021-002-nginx-resolver-copy/
author: Florian Roth (Nextron Systems)
date: 2021-05-31
modified: 2023-05-08
tags:
    - attack.impact
    - attack.t1499.004
logsource:
    service: nginx
detection:
    keywords:
        - 'exited on signal 6 (core dumped)'
    condition: keywords
falsepositives:
    - Serious issues with a configuration or plugin
level: high

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:
            # Enable
            - '/sysrq'
            - '/sysctl.conf'
            # Execute
            - '/sysrq-trigger'
    condition: selection
falsepositives:
    - Legitimate administrative activity
level: medium