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MALPEDIA_Win_Shrinklocker_Auto

autogenerated rule brought to you by yara-signator

MalwareShrinklockerMalpedia signator rulesCreative Commons Attribution-ShareAlike 4.0Compiles with YARA-X
Author
Felix Bilstein - yara-signator at cocacoding dot com
Date
2026-05-04
Modified
2026-05-18
Score / Quality
75 / 75

What this rule detects

autogenerated rule brought to you by yara-signator

Associated malware family: Shrinklocker.

It defines 10 patterns (0 text, 10 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

win-shrinklocker-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Shrinklocker_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "3c787fbd-bf0c-5d9a-9fba-067c6f540acd"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.shrinklocker"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.shrinklocker_auto.yar#L1-L131"
		license_url = "N/A"
		logic_hash = "d4695391c1b2664a33b20b19c2324c749b4af51c2b6b35bce8ae0c41f5a7efa8"
		score = 75
		quality = 75
		tags = "FILE"
		version = "1"
		tool = "yara-signator v0.6.0"
		signator_config = "callsandjumps;datarefs;binvalue"
		malpedia_rule_date = "20260422"
		malpedia_hash = "a182e35da64e6d71cb55f125c4d4225196523f14"
		malpedia_version = "20260504"
		malpedia_license = "CC BY-SA 4.0"
		malpedia_sharing = "TLP:WHITE"

	strings:
		$sequence_0 = { 488d4c2448 e8???????? 90 e9???????? 488b4c2470 e8???????? 4c8bc0 }
		$sequence_1 = { 4889442440 488d4c2470 e8???????? 4889442438 488b542438 488b4c2440 e8???????? }
		$sequence_2 = { 8b44245c 39442444 7608 8b44245c 89442444 837c244400 }
		$sequence_3 = { 483bc8 480f42f0 488d4e01 4885c9 7504 33ff }
		$sequence_4 = { eb07 488d15f1500300 488d4c2420 e8???????? be01000000 83630800 488d05175e0200 }
		$sequence_5 = { c1f803 89442420 488b842480000000 8b4c2420 8b4018 2bc1 }
		$sequence_6 = { 8d4401f0 488b4c2460 898110170000 eb48 0fb744240c 488b4c2460 8b8910170000 }
		$sequence_7 = { 83f801 751b 488b4308 488b08 488d0534070200 483901 7408 }
		$sequence_8 = { 7578 48630df866feff 488d15b566feff 4803ca 813950450000 755f b80b020000 }
		$sequence_9 = { 4889451f 33c0 488945c7 4183fe04 488d45b7 897dd7 4889442448 }

	condition:
		7 of them and filesize < 10490880
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ 488d4c2448 e8???????? 90 e9???????? 488b4c2470 e8???????? 4c8bc0 }
$sequence_1hex{ 4889442440 488d4c2470 e8???????? 4889442438 488b542438 488b4c2440 e8???????? }
$sequence_2hex{ 8b44245c 39442444 7608 8b44245c 89442444 837c244400 }
$sequence_3hex{ 483bc8 480f42f0 488d4e01 4885c9 7504 33ff }
$sequence_4hex{ eb07 488d15f1500300 488d4c2420 e8???????? be01000000 83630800 488d05175e0200 }
$sequence_5hex{ c1f803 89442420 488b842480000000 8b4c2420 8b4018 2bc1 }
$sequence_6hex{ 8d4401f0 488b4c2460 898110170000 eb48 0fb744240c 488b4c2460 8b8910170000 }
$sequence_7hex{ 83f801 751b 488b4308 488b08 488d0534070200 483901 7408 }
$sequence_8hex{ 7578 48630df866feff 488d15b566feff 4803ca 813950450000 755f b80b020000 }
$sequence_9hex{ 4889451f 33c0 488945c7 4183fe04 488d45b7 897dd7 4889442448 }

Condition

7 of them and filesize < 10490880

In plain words (Heuristic)

  • The file must be smaller than 10490880 (a cheap guard that skips large files).
  • At least 7 patterns in the rule must match.

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References

Licence & attribution

Author: Felix Bilstein - yara-signator at cocacoding dot com

Source repository: Malpedia signator rules @ c901f97b7d

Licence: Creative Commons Attribution-ShareAlike 4.0 (repository licence)

Original rule

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

Rule id: 3c787fbd-bf0c-5d9a-9fba-067c6f540acd

Metadata

version1
toolyara-signator v0.6.0
signator_configcallsandjumps;datarefs;binvalue
malpedia_rule_date20260422
malpedia_hasha182e35da64e6d71cb55f125c4d4225196523f14
malpedia_version20260504
malpedia_licenseCC BY-SA 4.0
malpedia_sharingTLP:WHITE

Tags:FILE