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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_MAL_Win_Amadey_Jun25

This rule detects intrinsic patterns of Amadey version 5.34

MalwareAmadeySignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
0x0d4y
Date
2025-06-18
Modified
2026-05-15
Score / Quality
80 / 85

What this rule detects

This rule detects intrinsic patterns of Amadey version 5.34

Associated malware family: Amadey.

Targets: Windows PE.

It defines 4 patterns (0 text, 4 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

mal-win-amadey-jun25.yarDetection Rule License 1.1
rule SIGNATURE_BASE_MAL_Win_Amadey_Jun25 : FILE
{
	meta:
		description = "This rule detects intrinsic patterns of Amadey version 5.34"
		author = "0x0d4y"
		id = "853111b8-e548-46a9-8f5a-ec8621343e0d"
		date = "2025-06-18"
		modified = "2026-05-15"
		reference = "https://0x0d4y.blog/amadey-targeted-analysis/"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/mal_win_amadey_jun25.yar#L1-L23"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		logic_hash = "08dc17aa8f7e83bc349339a9a1b48184b094d8c66273d7199a15b206c6416946"
		score = 80
		quality = 85
		tags = "FILE"
		yarahub_reference_md5 = "1db72c5832fb71b29863ccc3125137a0"
		license = "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
		malpedia_family = "win.amadey"

	strings:
		$rc4_algorithm = { 8a 96 ?? ?? ?? ?? 0f b6 86 ?? ?? ?? ?? 03 f8 0f b6 ca 03 f9 81 e7 ff 00 00 80 79 ?? 4f 81 cf 00 ff ff ff 47 8a 87 ?? ?? ?? ?? 88 86 ?? ?? ?? ?? 46 88 97 ?? ?? ?? ?? 81 fe 00 01 00 00 7c }
		$s_MZ_PE_validation = { b8 4d 5a ?? ?? 66 39 06 0f 85 a8 01 ?? ?? 8b 7e 3c 03 fe 81 3f 50 45 00 00  }
		$s_loop_through_pe_section = { 8b 4c 24 0c 03 ce 03 4e 3c 6a ?? ff b1 08 01 ?? ?? 8b 81 0c 01 00 00 03 c6 50 8b 81 04 01 ?? ?? 03 44 24 20 50 ff 74 24 30 ff 15 f4 f0 44 00 8b 4c 24 10 0f b7 47 06 41 83 44 24 0c 28 89 4c 24 10 3b c8 }
		$s_str_decryption_algorithm = { 8b cb 0f 43 35 ?? ?? ?? ?? 2b c8 8d 04 0a 33 d2 f7 f3 }

	condition:
		uint16( 0 ) == 0x5a4d and $rc4_algorithm and 2 of ( $s* )
}

Strings (4 patterns)

IdentifierTypeValueModifiers
$rc4_algorithmhex{ 8a 96 ?? ?? ?? ?? 0f b6 86 ?? ?? ?? ?? 03 f8 0f b6 ca 03 f9 81 e7 ff 00 00 80 79 ?? 4f 81 cf 00 ff ff ff 47 8a 87 ?? ?? ?? ?? 88 86 ?? ?? ?? ?? 46 88 97 ?? ?? …
$s_MZ_PE_validationhex{ b8 4d 5a ?? ?? 66 39 06 0f 85 a8 01 ?? ?? 8b 7e 3c 03 fe 81 3f 50 45 00 00 }
$s_loop_through_pe_sectionhex{ 8b 4c 24 0c 03 ce 03 4e 3c 6a ?? ff b1 08 01 ?? ?? 8b 81 0c 01 00 00 03 c6 50 8b 81 04 01 ?? ?? 03 44 24 20 50 ff 74 24 30 ff 15 f4 f0 44 00 8b 4c 24 10 0f b7 …
$s_str_decryption_algorithmhex{ 8b cb 0f 43 35 ?? ?? ?? ?? 2b c8 8d 04 0a 33 d2 f7 f3 }

Condition

uint16( 0 ) == 0x5a4d and $rc4_algorithm and 2 of ( $s* )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • At least 2 patterns in ( $s* ) must match.
  • Pattern $rc4_algorithm must be present.

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References

Licence & attribution

Author: 0x0d4y

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

Licence: Detection Rule License 1.1 (stated in the rule's own meta)

“Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE”

Original rule

Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.

Rule id: 853111b8-e548-46a9-8f5a-ec8621343e0d

Metadata

yarahub_reference_md51db72c5832fb71b29863ccc3125137a0
malpedia_familywin.amadey

Tags:FILE

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