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MALPEDIA_Win_Locky_Decryptor_Auto

autogenerated rule brought to you by yara-signator

MalwareLocky DecryptorMalpedia 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: Locky Decryptor.

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

Summary generated from the rule's metadata and condition.

Rule source

win-locky-decryptor-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Locky_Decryptor_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "ecfeaf41-63ea-55ed-b4aa-03611cff89ae"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.locky_decryptor"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.locky_decryptor_auto.yar#L1-L121"
		license_url = "N/A"
		logic_hash = "0702ae083d89f6bb2206cb125aaa99e0dffc193c2fefab2c47131b299ccaf228"
		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 = { 50 56 ff750c 895de8 8b3d???????? }
		$sequence_1 = { 50 56 e8???????? 83c40c 85ff 0f8435010000 }
		$sequence_2 = { 03c7 5a 2b5010 68???????? 01542410 8bf0 }
		$sequence_3 = { 8d4508 668378023a 7440 837d1c08 8b4508 7303 8d4508 }
		$sequence_4 = { c745f0b86b4100 e8???????? c9 c20c00 55 8bec 83ec10 }
		$sequence_5 = { 83c11c 4b 395c2414 7cc8 }
		$sequence_6 = { 7209 83ffff 0f879c000000 8d742424 e8???????? c644244c01 85db }
		$sequence_7 = { 57 8bc2 c1f805 8b048500c14100 }
		$sequence_8 = { 8d4db0 51 c645fc01 e8???????? 56 }
		$sequence_9 = { 50 56 53 8d742454 e8???????? 50 }

	condition:
		7 of them and filesize < 278528
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ 50 56 ff750c 895de8 8b3d???????? }
$sequence_1hex{ 50 56 e8???????? 83c40c 85ff 0f8435010000 }
$sequence_2hex{ 03c7 5a 2b5010 68???????? 01542410 8bf0 }
$sequence_3hex{ 8d4508 668378023a 7440 837d1c08 8b4508 7303 8d4508 }
$sequence_4hex{ c745f0b86b4100 e8???????? c9 c20c00 55 8bec 83ec10 }
$sequence_5hex{ 83c11c 4b 395c2414 7cc8 }
$sequence_6hex{ 7209 83ffff 0f879c000000 8d742424 e8???????? c644244c01 85db }
$sequence_7hex{ 57 8bc2 c1f805 8b048500c14100 }
$sequence_8hex{ 8d4db0 51 c645fc01 e8???????? 56 }
$sequence_9hex{ 50 56 53 8d742454 e8???????? 50 }

Condition

7 of them and filesize < 278528

In plain words (Heuristic)

  • The file must be smaller than 278528 (a cheap guard that skips large files).
  • At least 7 patterns in the rule must match.

Test this rule in your browser

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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: ecfeaf41-63ea-55ed-b4aa-03611cff89ae

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