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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:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "98c36664-9615-567e-b569-e03349b6a8f9"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.classfon"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.classfon_auto.yar#L1-L116"
		license_url = "N/A"
		logic_hash = "2e325492642d1a7d03123bb8a5e7c2d42eb730b5c05ad8d1538a0bf1f36caa6b"
		score = 75
		quality = 75
		tags = "FILE"
		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"

	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)

IdentifierTypeValueModifiers
$sequence_0hex{ f3ab 66ab 6804010000 8d4c241c }
$sequence_1hex{ e8???????? a1???????? 83c410 682b010000 }
$sequence_2hex{ 52 57 ffd6 8b742418 8b4b54 }
$sequence_3hex{ 6800010000 8d842450030000 52 50 }
$sequence_4hex{ 7429 03c6 85c0 740b 6a00 6a01 56 }
$sequence_5hex{ 33c0 8dbc244d040000 889c244c040000 f3ab 66ab aa 8d84241c010000 }
$sequence_6hex{ 6a04 52 ff15???????? 898608020000 5f b801000000 }
$sequence_7hex{ 897d04 89450c 894508 894510 8b4b50 }
$sequence_8hex{ 6a04 e8???????? 8b8424f0070000 83c418 83f801 7e16 }
$sequence_9hex{ 68???????? 6802000080 c744242402000080 896c242c }

Condition

7 of them and filesize < 73728

In 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.

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.

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References

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)

Original rule

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

version1
toolyara-signator v0.6.0
signator_configcallsandjumps;datarefs;binvalue
malpedia_rule_date20260422
malpedia_hasha182e35da64e6d71cb55f125c4d4225196523f14
malpedia_version20260504
malpedia_licenseCC BY-SA 4.0
malpedia_sharingTLP:WHITE

Tags:FILE