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SEKOIA_Apt_Yemen_Apk_Guardzoo

Detects Dex files containing GuardZoo strings.

APT / threat actorSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2024-08-09
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects Dex files containing GuardZoo strings.

It defines 9 patterns (9 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

apt-yemen-apk-guardzoo.yarDetection Rule License 1.1
rule SEKOIA_Apt_Yemen_Apk_Guardzoo : FILE
{
	meta:
		description = "Detects Dex files containing GuardZoo strings."
		author = "Sekoia.io"
		id = "f4004e7c-2904-46ea-a3e6-2bdd3e704fea"
		date = "2024-08-09"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_yemen_apk_guardzoo.yar#L1-L40"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		hash = "3afad114c68489e2d294720339baf570"
		hash = "c59d0f5c8d00485199f147b96c5abca0"
		hash = "75c58948725133160085dc1cfdf602ec"
		hash = "d76a39ee85263900f7e6eaacb804f5e2"
		hash = "51356c95dfe1221c0f4ca2475bc787f8"
		hash = "1d0dd8201c051d9c8d2c945c8b31a48c"
		hash = "b7b6be5e8eec44dd13e1df1f3908fcf0"
		hash = "229984f004578a8fa643afb881d81e8c"
		hash = "f3f1ccb3912c49a0a6ea710a0bd856de"
		hash = "a3f8365bfa5f8185e8c7eba8efc63165"
		hash = "7392deaf81ddf50b8a6f2179538f7e81"
		hash = "c40d56e1586f9fa382c688d624d25525"
		hash = "629fb04b91c4db4ea282440e20317dab"
		hash = "bcebc41628196f8bd119f72e1e8eb47c"
		hash = "f1cfdc9e91c3a20563246cf366b94f10"
		hash = "a75ffb11adbace40a7c59128adba43ad"
		logic_hash = "7d98aefa4c2ee7316e0ff47a67d9f19913852d1a451ef38ccb77709394e4ba73"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$classes_1 = "GuardZoo.java"
		$classes_2 = "com/animals"
		$path_1 = "&Password="
		$path_2 = "&Coordinates="
		$path_3 = "&Data="
		$path_4 = "&Device="
		$path_5 = "&ISPICTURE="
		$path_6 = "&Phone_Number="
		$path_7 = "&Provider="

	condition:
		uint32be( 0 ) == 0x6465780a and filesize < 10MB and ( ( any of ( $classes_* ) ) and ( 3 of ( $path_* ) ) )
}

Strings (9 patterns)

IdentifierTypeValueModifiers
$classes_1text"GuardZoo.java"
$classes_2text"com/animals"
$path_1text"&Password="
$path_2text"&Coordinates="
$path_3text"&Data="
$path_4text"&Device="
$path_5text"&ISPICTURE="
$path_6text"&Phone_Number="
$path_7text"&Provider="

Condition

uint32be( 0 ) == 0x6465780a and filesize < 10MB and ( ( any of ( $classes_* ) ) and ( 3 of ( $path_* ) ) )

In plain words (Heuristic)

  • The file must be smaller than 10MB (a cheap guard that skips large files).
  • At least one pattern in ( $classes_* ) must match.
  • At least 3 patterns in ( $path_* ) must match.

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References

Sample hashes

Hashes of samples the author lists in the rule's meta (look them up in your threat-intelligence platform).

  • 3afad114c68489e2d294720339baf570
  • c59d0f5c8d00485199f147b96c5abca0
  • 75c58948725133160085dc1cfdf602ec
  • d76a39ee85263900f7e6eaacb804f5e2
  • 51356c95dfe1221c0f4ca2475bc787f8
  • 1d0dd8201c051d9c8d2c945c8b31a48c
  • b7b6be5e8eec44dd13e1df1f3908fcf0
  • 229984f004578a8fa643afb881d81e8c
  • f3f1ccb3912c49a0a6ea710a0bd856de
  • a3f8365bfa5f8185e8c7eba8efc63165
  • 7392deaf81ddf50b8a6f2179538f7e81
  • c40d56e1586f9fa382c688d624d25525
  • 629fb04b91c4db4ea282440e20317dab
  • bcebc41628196f8bd119f72e1e8eb47c
  • f1cfdc9e91c3a20563246cf366b94f10
  • a75ffb11adbace40a7c59128adba43ad

Licence & attribution

Author: Sekoia.io

Source repository: SEKOIA.IO Community @ a438a5901a

Licence: Detection Rule License 1.1 (repository licence)

Original rule

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

Rule id: f4004e7c-2904-46ea-a3e6-2bdd3e704fea

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE