Detectionmediumtest
Creation of WerFault.exe/Wer.dll in Unusual Folder
Detects the creation of a file named "WerFault.exe" or "wer.dll" in an uncommon folder, which could be a sign of WerFault DLL hijacking.
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Log Source
WindowsFile Event
ProductWindows← raw: windows
CategoryFile Event← raw: file_event
Events for file system activity including creation, modification, and deletion.
Detection Logic
Detection Logic2 selectors
detection:
selection:
TargetFilename|endswith:
- '\WerFault.exe'
- '\wer.dll'
filter_main_known_locations:
TargetFilename|startswith:
- 'C:\Windows\SoftwareDistribution\'
- 'C:\Windows\System32\'
- 'C:\Windows\SysWOW64\'
- 'C:\Windows\WinSxS\'
- 'C:\Windows\UUS\arm64\'
condition: selection and not 1 of filter_main_*False Positives
Unknown
False positive likelihood has not been assessed. Additional context may be needed during triage.
References
MITRE ATT&CK
Rule Metadata
Rule ID
28a452f3-786c-4fd8-b8f2-bddbe9d616d1
Status
test
Level
medium
Type
Detection
Created
Mon May 09
Modified
Wed Dec 03
Author
Path
rules/windows/file/file_event/file_event_win_werfault_dll_hijacking.yml
Raw Tags
attack.privilege-escalationattack.persistenceattack.defense-evasionattack.t1574.001