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MALPEDIA_Win_Opachki_Auto

autogenerated rule brought to you by yara-signator

MalwareOpachkiMalpedia 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: Opachki.

It defines 15 patterns (0 text, 15 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

win-opachki-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Opachki_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "91723bbd-49de-5d2e-9be8-af9d048d21cd"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.opachki"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.opachki_auto.yar#L1-L155"
		license_url = "N/A"
		logic_hash = "4aabf4efe9abba6e7cdae995643de9ca627f9e08d6b1e7789a916de78aad53ac"
		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 = { 7452 8b5204 85d2 744b 2bf0 897508 7441 }
		$sequence_1 = { 53 8bd8 7413 8b4704 03c8 53 }
		$sequence_2 = { c3 55 8bec 81ec00010000 ff7508 }
		$sequence_3 = { ff15???????? 8b450c 8b4808 3bcb 7617 8b4004 53 }
		$sequence_4 = { 8bc3 2b45f8 ebf2 55 8bec }
		$sequence_5 = { 51 8b450c 56 8b7108 }
		$sequence_6 = { 8d4701 50 ff7604 89460c ff15???????? 59 59 }
		$sequence_7 = { 6a02 53 53 56 ff15???????? 8b450c }
		$sequence_8 = { 7514 08db 7409 80fe06 }
		$sequence_9 = { b201 ebc1 3c67 7507 }
		$sequence_10 = { 898389838983 898389838585 858585858585 878593859a9a }
		$sequence_11 = { f6c140 7412 08d2 7408 }
		$sequence_12 = { 4e 80ff01 7504 ac 884717 }
		$sequence_13 = { 30ff 08ed 7514 08db }
		$sequence_14 = { 7502 b704 4e 80ff01 }

	condition:
		7 of them and filesize < 122880
}

Strings (15 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ 7452 8b5204 85d2 744b 2bf0 897508 7441 }
$sequence_1hex{ 53 8bd8 7413 8b4704 03c8 53 }
$sequence_2hex{ c3 55 8bec 81ec00010000 ff7508 }
$sequence_3hex{ ff15???????? 8b450c 8b4808 3bcb 7617 8b4004 53 }
$sequence_4hex{ 8bc3 2b45f8 ebf2 55 8bec }
$sequence_5hex{ 51 8b450c 56 8b7108 }
$sequence_6hex{ 8d4701 50 ff7604 89460c ff15???????? 59 59 }
$sequence_7hex{ 6a02 53 53 56 ff15???????? 8b450c }
$sequence_8hex{ 7514 08db 7409 80fe06 }
$sequence_9hex{ b201 ebc1 3c67 7507 }
$sequence_10hex{ 898389838983 898389838585 858585858585 878593859a9a }
$sequence_11hex{ f6c140 7412 08d2 7408 }
$sequence_12hex{ 4e 80ff01 7504 ac 884717 }
$sequence_13hex{ 30ff 08ed 7514 08db }
$sequence_14hex{ 7502 b704 4e 80ff01 }

Condition

7 of them and filesize < 122880

In plain words (Heuristic)

  • The file must be smaller than 122880 (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: 91723bbd-49de-5d2e-9be8-af9d048d21cd

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