YARA · Signature Base (Florian Roth / Nextron)
SIGNATURE_BASE_MAL_Win_Amadey_Jun25
This rule detects intrinsic patterns of Amadey version 5.34
- 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
rule SIGNATURE_BASE_MAL_Win_Amadey_Jun25 : FILE
{
meta:
= "This rule detects intrinsic patterns of Amadey version 5.34"
= "0x0d4y"
= "853111b8-e548-46a9-8f5a-ec8621343e0d"
= "2025-06-18"
= "2026-05-15"
= "https://0x0d4y.blog/amadey-targeted-analysis/"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/mal_win_amadey_jun25.yar#L1-L23"
= "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
= "08dc17aa8f7e83bc349339a9a1b48184b094d8c66273d7199a15b206c6416946"
= 80
= 85
= "FILE"
= "1db72c5832fb71b29863ccc3125137a0"
= "Detection Rule License 1.1 https://github.com/Neo23x0/signature-base/blob/master/LICENSE"
= "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)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $rc4_algorithm | hex | { 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_validation | hex | { 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 | hex | { 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_algorithm | hex | { 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.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
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”
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_md5 | 1db72c5832fb71b29863ccc3125137a0 |
|---|---|
| malpedia_family | win.amadey |
Tags:FILE
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