YARA · Malpedia signator rules
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:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "3c787fbd-bf0c-5d9a-9fba-067c6f540acd"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.shrinklocker"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.shrinklocker_auto.yar#L1-L131"
= "N/A"
= "d4695391c1b2664a33b20b19c2324c749b4af51c2b6b35bce8ae0c41f5a7efa8"
= 75
= 75
= "FILE"
= "1"
= "yara-signator v0.6.0"
= "callsandjumps;datarefs;binvalue"
= "20260422"
= "a182e35da64e6d71cb55f125c4d4225196523f14"
= "20260504"
= "CC BY-SA 4.0"
= "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)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { 488d4c2448 e8???????? 90 e9???????? 488b4c2470 e8???????? 4c8bc0 } | |
| $sequence_1 | hex | { 4889442440 488d4c2470 e8???????? 4889442438 488b542438 488b4c2440 e8???????? } | |
| $sequence_2 | hex | { 8b44245c 39442444 7608 8b44245c 89442444 837c244400 } | |
| $sequence_3 | hex | { 483bc8 480f42f0 488d4e01 4885c9 7504 33ff } | |
| $sequence_4 | hex | { eb07 488d15f1500300 488d4c2420 e8???????? be01000000 83630800 488d05175e0200 } | |
| $sequence_5 | hex | { c1f803 89442420 488b842480000000 8b4c2420 8b4018 2bc1 } | |
| $sequence_6 | hex | { 8d4401f0 488b4c2460 898110170000 eb48 0fb744240c 488b4c2460 8b8910170000 } | |
| $sequence_7 | hex | { 83f801 751b 488b4308 488b08 488d0534070200 483901 7408 } | |
| $sequence_8 | hex | { 7578 48630df866feff 488d15b566feff 4803ca 813950450000 755f b80b020000 } | |
| $sequence_9 | hex | { 4889451f 33c0 488945c7 4183fe04 488d45b7 897dd7 4889442448 } |
Condition
7 of them and filesize < 10490880In 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.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.
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)
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
| 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 |
Tags:FILE
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