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DITEKSHEN_INDICATOR_Tool_Forensia

Detects Forensia anti-forensics tool used for erasing footprints

Suspicious / huntingditekSHen detectionBSD 2-Clause LicenseCompiles with YARA-X
Author
ditekSHen
Date
2020-11-06
Modified
2024-09-25
Score / Quality
75 / 73

What this rule detects

Detects Forensia anti-forensics tool used for erasing footprints

Targets: Windows PE.

It defines 21 patterns (20 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
indicator-tool-forensia.yarBSD 2-Clause License
rule DITEKSHEN_INDICATOR_Tool_Forensia : FILE
{
	meta:
		description = "Detects Forensia anti-forensics tool used for erasing footprints"
		author = "ditekSHen"
		id = "bcd05c2e-7ddd-5ce7-a6a7-0659bed38744"
		date = "2020-11-06"
		modified = "2024-09-25"
		reference = "https://github.com/ditekshen/detection"
		source_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/yara/indicator_tools.yar#L1490-L1523"
		license_url = "https://github.com/ditekshen/detection/blob/e76c93dcdedff04076380ffc60ea54e45b313635/LICENSE.txt"
		logic_hash = "7147eee62df10cd8a6c00ec80c4d1bdb8234a181dd6af81d0580d847f05bd0b6"
		score = 75
		quality = 73
		tags = "FILE"

	strings:
		$c1 = "for /F \"tokens=*\" %1 in ('wevtutil.exe el') DO wevtutil.exe cl \"%1\"" ascii
		$c2 = "del /F /Q C:\\Windows\\Prefetch\\*" ascii
		$c3 = "del C:\\Windows\\AppCompat\\Programs\\RecentFileCache.bcf" ascii
		$c4 = "del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\*" ascii
		$c5 = "del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\CustomDestinations\\*" ascii
		$c6 = "del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\AutomaticDestinations\\*" ascii
		$c7 = "fsutil.exe usn deletejournal /D C:" ascii
		$r1 = "\\Memory Management\\PrefetchParameters" wide
		$r2 = "\\Explorer\\Advanced" wide
		$r3 = "\\Services\\EventLog" wide
		$r4 = "\\Shell\\BagMRU" wide
		$r5 = "\\Control\\FileSystem" wide
		$r6 = "\\Setup\\VC" wide
		$s1 = "[LOG] - %s" wide
		$s2 = "\\forensia\\regedit.hpp" wide
		$s3 = "NtfsDisableLastAccessUpdate" wide
		$s4 = "Melting The Executable" wide
		$s5 = "Sysmon Unloader" wide
		$s6 = "Rundll32.exe apphelp.dll,ShimFlushCache" ascii
		$s7 = "\\Debug\\forensia.pdb" ascii
		$s8 = { 55 00 00 00 aa 00 00 00 92 49 24 00 49 24 92 00
                24 92 49 00 00 00 00 00 11 00 00 00 22 00 00 00
                33 00 00 00 44 00 00 00 66 00 00 00 88 00 00 00
                99 00 00 00 bb 00 00 00 cc 00 00 00 dd 00 00 00
                ee 00 00 00 ff 00 00 00 6d b6 db 00 b6 db 6d 00
                db 6d b6 }

	condition:
		uint16( 0 ) == 0x5a4d and ( ( 4 of ( $c* ) and 2 of ( $r* ) ) or ( 4 of ( $r* ) and 2 of ( $c* ) ) or 6 of ( $s* ) or ( 3 of ( $s* ) and 2 of ( $r* ) and 1 of ( $c* ) ) )
}

Strings (21 patterns)

IdentifierTypeValueModifiers
$c1text"for /F \"tokens=*\" %1 in ('wevtutil.exe el') DO wevtutil.exe cl \"%1\""ascii
$c2text"del /F /Q C:\\Windows\\Prefetch\\*"ascii
$c3text"del C:\\Windows\\AppCompat\\Programs\\RecentFileCache.bcf"ascii
$c4text"del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\*"ascii
$c5text"del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\CustomDestinations\\*"ascii
$c6text"del /F /Q %APPDATA%\\Microsoft\\Windows\\Recent\\AutomaticDestinations\\*"ascii
$c7text"fsutil.exe usn deletejournal /D C:"ascii
$r1text"\\Memory Management\\PrefetchParameters"wide
$r2text"\\Explorer\\Advanced"wide
$r3text"\\Services\\EventLog"wide
$r4text"\\Shell\\BagMRU"wide
$r5text"\\Control\\FileSystem"wide
$r6text"\\Setup\\VC"wide
$s1text"[LOG] - %s"wide
$s2text"\\forensia\\regedit.hpp"wide
$s3text"NtfsDisableLastAccessUpdate"wide
$s4text"Melting The Executable"wide
$s5text"Sysmon Unloader"wide
$s6text"Rundll32.exe apphelp.dll,ShimFlushCache"ascii
$s7text"\\Debug\\forensia.pdb"ascii
$s8hex{ 55 00 00 00 aa 00 00 00 92 49 24 00 49 24 92 00 24 92 49 00 00 00 00 00 11 00 00 00 22 00 00 00 33 00 00 00 44 00 00 00 66 00 …

Condition

uint16( 0 ) == 0x5a4d and ( ( 4 of ( $c* ) and 2 of ( $r* ) ) or ( 4 of ( $r* ) and 2 of ( $c* ) ) or 6 of ( $s* ) or ( 3 of ( $s* ) and 2 of ( $r* ) and 1 of ( $c* ) ) )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 4 patterns in ( $c* ) must match.
  • At least 2 patterns in ( $r* ) must match.
  • At least 4 patterns in ( $r* ) must match.
  • At least 2 patterns in ( $c* ) must match.
  • At least 6 patterns in ( $s* ) must match.
  • At least 3 patterns in ( $s* ) must match.
  • At least 1 patterns in ( $c* ) must match.

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References

Licence & attribution

Author: ditekSHen

Source repository: ditekSHen detection @ e76c93dcde

Licence: BSD 2-Clause License (repository licence)

Copyright notice: Copyright 2021 by ditekSHen (https://github.com/ditekshen/detection).

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: bcd05c2e-7ddd-5ce7-a6a7-0659bed38744

Tags:FILE

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