Skip to content

YARA · Malpedia signator rules

MALPEDIA_Win_Final1Stspy_Auto

autogenerated rule brought to you by yara-signator

MalwareFinal1StspyMalpedia 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: Final1Stspy.

It defines 10 patterns (0 text, 10 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

win-final1stspy-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Final1Stspy_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "beac32f0-9535-5d04-afb4-171b3f49950a"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.final1stspy"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.final1stspy_auto.yar#L1-L120"
		license_url = "N/A"
		logic_hash = "57b7ed39671ff3bcfc0a4a76a09b0a2fd05899d02fe784b6638f16c1d57de809"
		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 = { 8bf8 81e7ff070080 7908 4f 81cf00f8ffff 47 33f6 }
		$sequence_1 = { 8bf8 81e7ff070080 7908 4f 81cf00f8ffff }
		$sequence_2 = { 803900 7426 8a1d???????? 33ff }
		$sequence_3 = { 5e 83c8ff 5b 8be5 5d c3 81e9???????? }
		$sequence_4 = { 6690 3acd 7412 8a4801 40 84c9 }
		$sequence_5 = { 81cf00feffff 47 33f6 85ff 7e0a }
		$sequence_6 = { 85ff 7e0a e8???????? 46 3bf7 7cf6 }
		$sequence_7 = { 57 8b7dfc 83fe20 724a 251f000080 7905 48 }
		$sequence_8 = { 56 8bf0 8945fc 57 8d7e01 }
		$sequence_9 = { 894df8 8bf1 8b4dfc 803900 }

	condition:
		7 of them and filesize < 557056
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ 8bf8 81e7ff070080 7908 4f 81cf00f8ffff 47 33f6 }
$sequence_1hex{ 8bf8 81e7ff070080 7908 4f 81cf00f8ffff }
$sequence_2hex{ 803900 7426 8a1d???????? 33ff }
$sequence_3hex{ 5e 83c8ff 5b 8be5 5d c3 81e9???????? }
$sequence_4hex{ 6690 3acd 7412 8a4801 40 84c9 }
$sequence_5hex{ 81cf00feffff 47 33f6 85ff 7e0a }
$sequence_6hex{ 85ff 7e0a e8???????? 46 3bf7 7cf6 }
$sequence_7hex{ 57 8b7dfc 83fe20 724a 251f000080 7905 48 }
$sequence_8hex{ 56 8bf0 8945fc 57 8d7e01 }
$sequence_9hex{ 894df8 8bf1 8b4dfc 803900 }

Condition

7 of them and filesize < 557056

In plain words (Heuristic)

  • The file must be smaller than 557056 (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.

Open in editor

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: beac32f0-9535-5d04-afb4-171b3f49950a

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