YARA · Malpedia signator rules
MALPEDIA_Win_Classfon_Auto
autogenerated rule brought to you by yara-signator
MalwareClassfonMalpedia 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: Classfon.
It defines 10 patterns (0 text, 10 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
win-classfon-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Classfon_Auto : FILE
{
meta:
= "autogenerated rule brought to you by yara-signator"
= "Felix Bilstein - yara-signator at cocacoding dot com"
= "98c36664-9615-567e-b569-e03349b6a8f9"
= "2026-05-04"
= "2026-05-18"
= "https://malpedia.caad.fkie.fraunhofer.de/details/win.classfon"
= "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.classfon_auto.yar#L1-L116"
= "N/A"
= "2e325492642d1a7d03123bb8a5e7c2d42eb730b5c05ad8d1538a0bf1f36caa6b"
= 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 = { f3ab 66ab 6804010000 8d4c241c }
$sequence_1 = { e8???????? a1???????? 83c410 682b010000 }
$sequence_2 = { 52 57 ffd6 8b742418 8b4b54 }
$sequence_3 = { 6800010000 8d842450030000 52 50 }
$sequence_4 = { 7429 03c6 85c0 740b 6a00 6a01 56 }
$sequence_5 = { 33c0 8dbc244d040000 889c244c040000 f3ab 66ab aa 8d84241c010000 }
$sequence_6 = { 6a04 52 ff15???????? 898608020000 5f b801000000 }
$sequence_7 = { 897d04 89450c 894508 894510 8b4b50 }
$sequence_8 = { 6a04 e8???????? 8b8424f0070000 83c418 83f801 7e16 }
$sequence_9 = { 68???????? 6802000080 c744242402000080 896c242c }
condition:
7 of them and filesize < 73728
}
Strings (10 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $sequence_0 | hex | { f3ab 66ab 6804010000 8d4c241c } | |
| $sequence_1 | hex | { e8???????? a1???????? 83c410 682b010000 } | |
| $sequence_2 | hex | { 52 57 ffd6 8b742418 8b4b54 } | |
| $sequence_3 | hex | { 6800010000 8d842450030000 52 50 } | |
| $sequence_4 | hex | { 7429 03c6 85c0 740b 6a00 6a01 56 } | |
| $sequence_5 | hex | { 33c0 8dbc244d040000 889c244c040000 f3ab 66ab aa 8d84241c010000 } | |
| $sequence_6 | hex | { 6a04 52 ff15???????? 898608020000 5f b801000000 } | |
| $sequence_7 | hex | { 897d04 89450c 894508 894510 8b4b50 } | |
| $sequence_8 | hex | { 6a04 e8???????? 8b8424f0070000 83c418 83f801 7e16 } | |
| $sequence_9 | hex | { 68???????? 6802000080 c744242402000080 896c242c } |
Condition
7 of them and filesize < 73728In plain words (Heuristic)
- The file must be smaller than 73728 (a cheap guard that skips large files).
- At least 7 patterns in the rule must match.
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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: 98c36664-9615-567e-b569-e03349b6a8f9
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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