Sigma rule: WinRAR Creating Files in Startup Locations

Rule

Title

WinRAR Creating Files in Startup Locations

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-07-16

File

rules/windows/file/file_event/file_event_win_winrar_file_creation_in_startup_folder.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects WinRAR creating files in Windows startup locations, which may indicate an attempt to establish persistence by adding malicious files to the Startup folder.
This kind of behaviour has been associated with exploitation of WinRAR path traversal vulnerability CVE-2025-6218 or CVE-2025-8088.

Log source

product

windows

category

file_event

Detection

selection:
    Image|endswith:
        - '\WinRAR.exe'
        - '\Rar.exe'
    TargetFilename|contains: '\Start Menu\Programs\Startup\'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.persistence
• attack.t1547.001

MITRE ATT&CK ids this rule names

• T1547.001

References

• https://github.com/mulwareX/CVE-2025-6218-POC
• https://x.com/0x534c/status/1944694507787710685
• https://www.welivesecurity.com/en/eset-research/update-winrar-tools-now-romcom-and-others-exploiting-zero-day-vulnerability/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/file/file_event/file_event_win_winrar_file_creation_in_startup_folder.yml