YARA · SEKOIA.IO Community
SEKOIA_Guloader_Unpacker_Decoded
GuLoader Unpacker b64 decoded
- Author
- Sekoia.io
- Date
- 2024-02-07
- Modified
- 2024-12-19
- Score / Quality
- 75 / 80
What this rule detects
GuLoader Unpacker b64 decoded
It defines 4 patterns (3 text, 1 hex, 0 regex).
Summary generated from the rule's metadata and condition.
Rule source
guloader-unpacker-decoded.yarDetection Rule License 1.1
rule SEKOIA_Guloader_Unpacker_Decoded : FILE
{
meta:
= "GuLoader Unpacker b64 decoded"
= "Sekoia.io"
= "ca3f4fce-b3a1-4672-a2ca-29ea347eb23d"
= "2024-02-07"
= "2024-12-19"
= "https://github.com/SEKOIA-IO/Community"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/guloader_unpacker_decoded.yar#L1-L18"
= "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
= "5de4a147b2dea8a144905b7f1786199bfeef3006ac58179409cfd3dcaa116725"
= 75
= 80
= "FILE"
= "1.0"
= "TLP:CLEAR"
strings:
$jumps = {71 01 9b 71 01 9b}
$s1 = "([String]$"
$s2 = "For($"
$s3 = ",[Parameter(Position = 1)] [Type] $"
condition:
filesize < 500KB and @jumps < 1000 and 2 of ( $s* )
}
Strings (4 patterns)
| Identifier | Type | Value | Modifiers |
|---|---|---|---|
| $jumps | hex | {71 01 9b 71 01 9b} | |
| $s1 | text | "([String]$" | |
| $s2 | text | "For($" | |
| $s3 | text | ",[Parameter(Position = 1)] [Type] $" |
Condition
filesize < 500KB and @jumps < 1000 and 2 of ( $s* )In plain words (Heuristic)
- The file must be smaller than 500KB (a cheap guard that skips large files).
- At least 2 patterns in ( $s* ) must match.
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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: ca3f4fce-b3a1-4672-a2ca-29ea347eb23d
Metadata
| version | 1.0 |
|---|---|
| classification | TLP:CLEAR |
Tags:FILE
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