YARA · Malpedia signator rules
MALPEDIA_Win_Karsto_Rat_Auto
autogenerated rule brought to you by yara-signator
MalwareKarsto RatMalpedia 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: Karsto Rat.
It defines 10 patterns (0 text, 10 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
win-karsto-rat-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Karsto_Rat_Auto : FILE
{
meta:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "c34bf4f5-4b74-55dd-a22e-8744ec3fa2a0"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.karsto_rat"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.karsto_rat_auto.yar#L1-L131"
= "N/A"
= "9bd1e4ab59a6417a010bca0942b95855a3ad41d78472f9a8e3faff9facca4a0f"
= 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 = { c744242000000080 4533c9 4533c0 498bce ff15???????? 4c8bf8 4885c0 }
$sequence_1 = { 4883e6e0 488946f8 eb08 e8???????? 488bf0 4c8bc7 }
$sequence_2 = { d2e0 2206 48ffc6 0ad0 8817 48ffc7 498bd9 }
$sequence_3 = { 83ff02 0f84b1020000 83f802 0f84a8020000 f7437000010000 440fb67374 742b }
$sequence_4 = { 4883f90f 7603 488b3b 488d05f26a0100 41bc1c000000 4c8d3dc96a0100 }
$sequence_5 = { 483bd8 773f 48897c2440 488d0419 48894610 488bc6 4983f80f }
$sequence_6 = { 0f104f10 0f114b10 0f1117 0f115f10 4883c420 415e }
$sequence_7 = { ff15???????? 488d4de8 48837d000f 480f474de8 4533c9 4533c0 33d2 }
$sequence_8 = { 837b7c5e 488d737c 7569 488b4348 83700c01 488b03 488b5310 }
$sequence_9 = { 48ffc1 4883c90f 493bcf 7613 498bff 48b90000000000000080 4883c127 }
condition:
7 of them and filesize < 336896
}
Strings (10 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { c744242000000080 4533c9 4533c0 498bce ff15???????? 4c8bf8 4885c0 } | |
| $sequence_1 | hex | { 4883e6e0 488946f8 eb08 e8???????? 488bf0 4c8bc7 } | |
| $sequence_2 | hex | { d2e0 2206 48ffc6 0ad0 8817 48ffc7 498bd9 } | |
| $sequence_3 | hex | { 83ff02 0f84b1020000 83f802 0f84a8020000 f7437000010000 440fb67374 742b } | |
| $sequence_4 | hex | { 4883f90f 7603 488b3b 488d05f26a0100 41bc1c000000 4c8d3dc96a0100 } | |
| $sequence_5 | hex | { 483bd8 773f 48897c2440 488d0419 48894610 488bc6 4983f80f } | |
| $sequence_6 | hex | { 0f104f10 0f114b10 0f1117 0f115f10 4883c420 415e } | |
| $sequence_7 | hex | { ff15???????? 488d4de8 48837d000f 480f474de8 4533c9 4533c0 33d2 } | |
| $sequence_8 | hex | { 837b7c5e 488d737c 7569 488b4348 83700c01 488b03 488b5310 } | |
| $sequence_9 | hex | { 48ffc1 4883c90f 493bcf 7613 498bff 48b90000000000000080 4883c127 } |
Condition
7 of them and filesize < 336896In plain words (Heuristic)
- The file must be smaller than 336896 (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: c34bf4f5-4b74-55dd-a22e-8744ec3fa2a0
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
Related rules
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04
- MalwareMalpedia signator rules· Felix Bilstein - yara-signator at cocacoding dot com· 2026-05-04