YARA · Malpedia signator rules
MALPEDIA_Win_Cmstar_Auto
autogenerated rule brought to you by yara-signator
- 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: Cmstar.
It defines 16 patterns (0 text, 16 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
win-cmstar-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Cmstar_Auto : FILE
{
meta:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "1be886c8-9b51-5137-aeaf-a67c65367096"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.cmstar"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.cmstar_auto.yar#L1-L169"
= "N/A"
= "af8082749fad46b0a710f9a3a1351eedc3f8a705b721d9a56ae6d475cb1d94e2"
= 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 = { ff15???????? 6a03 58 5f 5e 5b c9 }
$sequence_1 = { 8b4dec c1e802 6a04 52 8d0481 50 }
$sequence_2 = { 8b45d8 836dfc10 ff75fc 8945e0 8b45dc 83c310 }
$sequence_3 = { 7504 6a03 eb0d 803b4d }
$sequence_4 = { ff75e4 8b45e8 ff75e0 ff30 e8???????? 8b4df8 }
$sequence_5 = { 8bc6 e9???????? 6a10 8d45d0 }
$sequence_6 = { ff15???????? 6a04 e8???????? be00040000 }
$sequence_7 = { 56 bb04010000 57 53 }
$sequence_8 = { 6a00 6a01 8d4c242c 6800000080 51 }
$sequence_9 = { 895c2420 895c241c 895c2428 c74424303c000000 }
$sequence_10 = { 68???????? 890d???????? 56 890d???????? c705????????01000000 }
$sequence_11 = { 6a00 6a04 6a00 6a02 6800000040 50 ffd3 }
$sequence_12 = { f3a5 8bc8 33c0 83e103 668b15???????? }
$sequence_13 = { 99 f7fb 80c220 88140e 41 3bcb 7cea }
$sequence_14 = { 7506 8b35???????? bf???????? 83c9ff 33c0 6a00 f2ae }
$sequence_15 = { 895908 89590c a1???????? 8b10 52 53 }
condition:
7 of them and filesize < 4268032
}
Strings (16 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { ff15???????? 6a03 58 5f 5e 5b c9 } | |
| $sequence_1 | hex | { 8b4dec c1e802 6a04 52 8d0481 50 } | |
| $sequence_2 | hex | { 8b45d8 836dfc10 ff75fc 8945e0 8b45dc 83c310 } | |
| $sequence_3 | hex | { 7504 6a03 eb0d 803b4d } | |
| $sequence_4 | hex | { ff75e4 8b45e8 ff75e0 ff30 e8???????? 8b4df8 } | |
| $sequence_5 | hex | { 8bc6 e9???????? 6a10 8d45d0 } | |
| $sequence_6 | hex | { ff15???????? 6a04 e8???????? be00040000 } | |
| $sequence_7 | hex | { 56 bb04010000 57 53 } | |
| $sequence_8 | hex | { 6a00 6a01 8d4c242c 6800000080 51 } | |
| $sequence_9 | hex | { 895c2420 895c241c 895c2428 c74424303c000000 } | |
| $sequence_10 | hex | { 68???????? 890d???????? 56 890d???????? c705????????01000000 } | |
| $sequence_11 | hex | { 6a00 6a04 6a00 6a02 6800000040 50 ffd3 } | |
| $sequence_12 | hex | { f3a5 8bc8 33c0 83e103 668b15???????? } | |
| $sequence_13 | hex | { 99 f7fb 80c220 88140e 41 3bcb 7cea } | |
| $sequence_14 | hex | { 7506 8b35???????? bf???????? 83c9ff 33c0 6a00 f2ae } | |
| $sequence_15 | hex | { 895908 89590c a1???????? 8b10 52 53 } |
Condition
7 of them and filesize < 4268032In plain words (Heuristic)
- The file must be smaller than 4268032 (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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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: 1be886c8-9b51-5137-aeaf-a67c65367096
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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