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MALPEDIA_Win_Maskgramstealer_Auto

autogenerated rule brought to you by yara-signator

MalwareMaskgramstealerMalpedia 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: Maskgramstealer.

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

Summary generated from the rule's metadata and condition.

Rule source

win-maskgramstealer-auto.yarCreative Commons Attribution-ShareAlike 4.0
rule MALPEDIA_Win_Maskgramstealer_Auto : FILE
{
	meta:
		description = "autogenerated rule brought to you by yara-signator"
		author = "Felix Bilstein - yara-signator at cocacoding dot com"
		id = "4ee1204a-c4f7-5140-8868-3ec21d80ad68"
		date = "2026-05-04"
		modified = "2026-05-18"
		reference = "https://malpedia.caad.fkie.fraunhofer.de/details/win.maskgramstealer"
		source_url = "https://github.com/malpedia/signator-rules//blob/c901f97b7df03e41917da74c2a84b04c227316c2/rules/win.maskgramstealer_auto.yar#L1-L113"
		license_url = "N/A"
		logic_hash = "aaf8addcd84a5405900df60d1e4cadcf3baed2d226e1d47976eaeb2f5bfc316c"
		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 = { 48ffc2 807c11ff00 75f3 c3 }
		$sequence_1 = { 4c39c0 7412 448a0c02 4584c9 7409 44880c01 48ffc0 }
		$sequence_2 = { c3 31c0 448a0402 4584c0 }
		$sequence_3 = { 7503 48ffc2 4c89d1 e8???????? 4c89d1 e8???????? }
		$sequence_4 = { 48833d????????00 0f95c2 4885c0 0f95c0 }
		$sequence_5 = { e9???????? 4881c428060000 5b 5e 5f }
		$sequence_6 = { 8a02 3c5c 7404 3c2f 7503 }
		$sequence_7 = { 488b0d???????? 488b1d???????? ffd3 488b0d???????? ffd3 }
		$sequence_8 = { 8b8c24b0060000 488d942480000000 e8???????? 83bc24b006000000 }
		$sequence_9 = { 498d1400 8a02 3c5c 7404 3c2f }

	condition:
		7 of them and filesize < 353280
}

Strings (10 patterns)

IdentifierTypeValueModifiers
$sequence_0hex{ 48ffc2 807c11ff00 75f3 c3 }
$sequence_1hex{ 4c39c0 7412 448a0c02 4584c9 7409 44880c01 48ffc0 }
$sequence_2hex{ c3 31c0 448a0402 4584c0 }
$sequence_3hex{ 7503 48ffc2 4c89d1 e8???????? 4c89d1 e8???????? }
$sequence_4hex{ 48833d????????00 0f95c2 4885c0 0f95c0 }
$sequence_5hex{ e9???????? 4881c428060000 5b 5e 5f }
$sequence_6hex{ 8a02 3c5c 7404 3c2f 7503 }
$sequence_7hex{ 488b0d???????? 488b1d???????? ffd3 488b0d???????? ffd3 }
$sequence_8hex{ 8b8c24b0060000 488d942480000000 e8???????? 83bc24b006000000 }
$sequence_9hex{ 498d1400 8a02 3c5c 7404 3c2f }

Condition

7 of them and filesize < 353280

In plain words (Heuristic)

  • The file must be smaller than 353280 (a cheap guard that skips large files).
  • At least 7 patterns in the rule must match.

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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: 4ee1204a-c4f7-5140-8868-3ec21d80ad68

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