YARA · SEKOIA.IO Community
SEKOIA_Apt_Apt28_Susp_Graphite_Downloader
Matches the routine which decrypts the RSA key blob in the Graphite downloader
- Author
- Sekoia.io
- Date
- 2022-01-26
- Modified
- 2024-12-19
- Score / Quality
- 65 / 80
What this rule detects
Matches the routine which decrypts the RSA key blob in the Graphite downloader
Associated malware family: Graphite.
Targets: Windows PE.
It defines 1 patterns (0 text, 1 hex, 0 regex). YARA modules used: pe.
Summary generated from the rule's metadata and condition.
Rule source
Includes the imports needed to compile it on its own.
import "pe"
rule SEKOIA_Apt_Apt28_Susp_Graphite_Downloader : FILE
{
meta:
= "Matches the routine which decrypts the RSA key blob in the Graphite downloader"
= "Sekoia.io"
= "9c9da5fe-ffd6-4c45-8ce1-9a6cf4fa2fda"
= "2022-01-26"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_apt28_susp_graphite_downloader.yar#L3-L26"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "ca5aa7ea995aca9003fd98da2fba7bbec1e049d979a6b05e07b80876bab5a1c9"
= 65
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$gen = { 33 D2
8B C1
6A ??
5E
F7 F6
8A 82 ?? ?? ?? ??
30 81 ?? ?? ?? ??
41
81 F9 94 04 00 00
72 E2 }
condition:
uint16be( 0 ) == 0x4d5a and $gen and pe.number_of_exports == 1
}
Strings (1 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $gen | hex | { 33 D2 8B C1 6A ?? 5E F7 F6 8A 82 ?? ?? ?? ?? 30 81 ?? ?? ?? ?? 41 81 F9 94 04 00 00 72 … |
Condition
uint16be( 0 ) == 0x4d5a and $gen and pe.number_of_exports == 1In plain words (Heuristic)
- The file must start with “MZ” — a Windows executable (PE).
- Pattern $gen must be present.
- Uses the pe module.
- Checks exported functions or the DLL name.
Test this rule in your browser
Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.
References
Licence & attribution
Author: Sekoia.io
Source repository: SEKOIA.IO Community @ a438a5901a
Licence: Detection Rule License 1.1 (repository licence)
Mirrored via YARA Forge 20260927, which prefixes rule names with the source and adds normalised meta fields.
Rule id: 9c9da5fe-ffd6-4c45-8ce1-9a6cf4fa2fda
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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