Non-depmod Process Modifying modules.dep

 1title: Non-depmod Process Modifying modules.dep
 2id: c0bbc749-9ed3-483b-b3ac-7c5732a61fda
 3status: experimental
 4description: |
 5    Detects unusual process modifying the modules.dep file. The modules.dep and modules.dep.bin 
 6    files should only be modified by the depmod utility. Part of the RedCanary 2024 Threat 
 7    Detection Report.    
 8references:
 9    - https://redcanary.com/threat-detection-report/techniques/kernel-modules-and-extensions/
10author: RedCanary, Sigma formatting by Micah Babinski
11date: 2024/03/21
12tags:
13    - attack.persistence
14    - attack.privilege_escalation
15    - attack.t1547
16    - attack.t1547.006
17logsource:
18    product: linux
19    category: file_event
20detection:
21    selection:
22        TargetFilename|startswith: '/lib/modules/'
23        TargetFilename|endswith:
24            - '/modules.dep'
25            - '/modules.dep.bin'
26    filter:
27        Image|endswith: '/depmod'
28    condition: selection and not filter
29falsepositives:
30    - Unknown
31level: low```