YARA · Malpedia signator rules
MALPEDIA_Win_Reactorbot_Auto
autogenerated rule brought to you by yara-signator
MalwareReactorbotMalpedia 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: Reactorbot.
It defines 16 patterns (0 text, 16 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
win-reactorbot-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Reactorbot_Auto : FILE
{
meta:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "4655650a-c24e-5848-9e67-49f0a752ad4b"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.reactorbot"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.reactorbot_auto.yar#L1-L158"
= "N/A"
= "ff171c08eb3d99e1db9fc775e00a58387c90f546379a4da228edb0903024af0e"
= 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 = { 81ec980c0000 c745f400000000 c745e800000000 c745e400000000 a1???????? }
$sequence_1 = { 8bec 833d????????00 7418 6aff a1???????? 50 ff15???????? }
$sequence_2 = { 8945ec 837decff 7505 e9???????? 837de800 }
$sequence_3 = { 6804010000 8d8d88fbffff 51 e8???????? 8b9590fdffff }
$sequence_4 = { 51 ff15???????? 8b55f0 3b55fc }
$sequence_5 = { a1???????? 8945e0 8b4d08 51 ff15???????? }
$sequence_6 = { 52 e8???????? 8d85bcfdffff 50 6804010000 }
$sequence_7 = { 7420 8b0d???????? 51 8b15???????? 52 }
$sequence_8 = { 6bc005 83e803 99 b999000000 }
$sequence_9 = { 7402 eb0c c705????????b80b0000 eb0a }
$sequence_10 = { 83e101 f7d9 81e12083b8ed 33c1 }
$sequence_11 = { 69c0b13a0200 99 83e203 03c2 }
$sequence_12 = { 83c005 99 b905000000 f7f9 }
$sequence_13 = { e8???????? 833d????????00 7509 833d????????00 740b }
$sequence_14 = { 05add92400 89442424 8b442424 ffc0 99 b907000000 }
$sequence_15 = { c744247800000000 c744245000000000 c744247c00000000 c744246000000000 }
condition:
7 of them and filesize < 1032192
}
Strings (16 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { 81ec980c0000 c745f400000000 c745e800000000 c745e400000000 a1???????? } | |
| $sequence_1 | hex | { 8bec 833d????????00 7418 6aff a1???????? 50 ff15???????? } | |
| $sequence_2 | hex | { 8945ec 837decff 7505 e9???????? 837de800 } | |
| $sequence_3 | hex | { 6804010000 8d8d88fbffff 51 e8???????? 8b9590fdffff } | |
| $sequence_4 | hex | { 51 ff15???????? 8b55f0 3b55fc } | |
| $sequence_5 | hex | { a1???????? 8945e0 8b4d08 51 ff15???????? } | |
| $sequence_6 | hex | { 52 e8???????? 8d85bcfdffff 50 6804010000 } | |
| $sequence_7 | hex | { 7420 8b0d???????? 51 8b15???????? 52 } | |
| $sequence_8 | hex | { 6bc005 83e803 99 b999000000 } | |
| $sequence_9 | hex | { 7402 eb0c c705????????b80b0000 eb0a } | |
| $sequence_10 | hex | { 83e101 f7d9 81e12083b8ed 33c1 } | |
| $sequence_11 | hex | { 69c0b13a0200 99 83e203 03c2 } | |
| $sequence_12 | hex | { 83c005 99 b905000000 f7f9 } | |
| $sequence_13 | hex | { e8???????? 833d????????00 7509 833d????????00 740b } | |
| $sequence_14 | hex | { 05add92400 89442424 8b442424 ffc0 99 b907000000 } | |
| $sequence_15 | hex | { c744247800000000 c744245000000000 c744247c00000000 c744246000000000 } |
Condition
7 of them and filesize < 1032192In plain words (Heuristic)
- The file must be smaller than 1032192 (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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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: 4655650a-c24e-5848-9e67-49f0a752ad4b
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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