Skip to content

YARA · Malpedia signator rules

MALPEDIA_Win_Mystic_Stealer_Auto

autogenerated rule brought to you by yara-signator

MalwareMystic StealerMalpedia 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: Mystic Stealer.

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

Summary generated from the rule's metadata and condition.

Rule source

win-mystic-stealer-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Mystic_Stealer_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "669e0d29-c98f-59de-8cf5-902f29ae3a52"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.mystic_stealer"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.mystic_stealer_auto.yar#L1-L114"
		license_url = "N/A"
		logic_hash = "21ec795eb8ab4014e3a067a382badfa4fd3bac788790ebafb7beb557561dc9fc"
		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 = { c7460445000000 8b4e04 8d6e1c 83f945 }
		$sequence_1 = { 234754 83bfb416000000 894748 7452 8b4738 8b4f58 }
		$sequence_2 = { 668bc7 66d3e0 660bc5 0fb7c8 }
		$sequence_3 = { 8b4c241c 83c40c 8b4500 034e14 894e14 }
		$sequence_4 = { 8d040a 0fb78fb8160000 660bf1 0fb7ce }
		$sequence_5 = { 8386bc160000f3 b110 2ac8 66d3ef 0fb7c7 }
		$sequence_6 = { 80ea03 c6040101 8b8ea0160000 8b8698160000 41 898ea0160000 c6040100 }
		$sequence_7 = { 59 59 ffd0 8be8 }
		$sequence_8 = { 898550140000 898c855c0b0000 33c0 40 6689048b c684295814000000 ff8da8160000 }
		$sequence_9 = { 33db 668987b8160000 85ed 0f8ea0000000 }

	condition:
		7 of them and filesize < 512000
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ c7460445000000 8b4e04 8d6e1c 83f945 }
$sequence_1hex{ 234754 83bfb416000000 894748 7452 8b4738 8b4f58 }
$sequence_2hex{ 668bc7 66d3e0 660bc5 0fb7c8 }
$sequence_3hex{ 8b4c241c 83c40c 8b4500 034e14 894e14 }
$sequence_4hex{ 8d040a 0fb78fb8160000 660bf1 0fb7ce }
$sequence_5hex{ 8386bc160000f3 b110 2ac8 66d3ef 0fb7c7 }
$sequence_6hex{ 80ea03 c6040101 8b8ea0160000 8b8698160000 41 898ea0160000 c6040100 }
$sequence_7hex{ 59 59 ffd0 8be8 }
$sequence_8hex{ 898550140000 898c855c0b0000 33c0 40 6689048b c684295814000000 ff8da8160000 }
$sequence_9hex{ 33db 668987b8160000 85ed 0f8ea0000000 }

Condition

7 of them and filesize < 512000

In plain words (Heuristic)

  • The file must be smaller than 512000 (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: 669e0d29-c98f-59de-8cf5-902f29ae3a52

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