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SEKOIA_Apt_Cloudmensis_Spyagent_Strings

Detects CloudMensis SpyAgent

APT / threat actorSEKOIA.IO CommunityDetection Rule License 1.1Compiles with YARA-X
Author
Sekoia.io
Date
2022-07-26
Modified
2024-12-19
Score / Quality
75 / 80

What this rule detects

Detects CloudMensis SpyAgent

Targets: macOS Mach-O.

It defines 5 patterns (5 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

apt-cloudmensis-spyagent-strings.yarDetection Rule License 1.1
rule SEKOIA_Apt_Cloudmensis_Spyagent_Strings : FILE
{
	meta:
		description = "Detects CloudMensis SpyAgent"
		author = "Sekoia.io"
		id = "c2df8373-6698-4b23-9d77-8e7968bd69f0"
		date = "2022-07-26"
		modified = "2024-12-19"
		reference = "https://github.com/SEKOIA-IO/Community"
		source_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/yara_rules/apt_cloudmensis_spyagent_strings.yar#L1-L21"
		license_url = "https://github.com/SEKOIA-IO/Community/blob/a438a5901a211c2abdf75da9c93921ef187473d1/LICENSE.md"
		logic_hash = "ad858b1b78fb4ac6efee093b11fde14956d63bc6b300ef37bf1f2a3356cf4402"
		score = 75
		quality = 80
		tags = "FILE"
		version = "1.0"
		classification = "TLP:CLEAR"

	strings:
		$ = "[control_thread loop_DirStructure:]"
		$ = "[screen_keylog getScreenShotData]"
		$ = "[screen_keylog loop_usb]"
		$ = "[Management UploadFilebyPath:destination:]"
		$ = "[control_thread loop_pwd:]"

	condition:
		uint32be( 0 ) == 0xcafebabe and filesize < 2MB and all of them
}

Strings (5 patterns)

IdentifierTypeValueModifiers
$text"[control_thread loop_DirStructure:]"
$text"[screen_keylog getScreenShotData]"
$text"[screen_keylog loop_usb]"
$text"[Management UploadFilebyPath:destination:]"
$text"[control_thread loop_pwd:]"

Condition

uint32be( 0 ) == 0xcafebabe and filesize < 2MB and all of them

In plain words (Heuristic)

  • The file must start with a Mach-O / fat binary magic — a macOS executable.
  • The file must be smaller than 2MB (a cheap guard that skips large files).
  • All patterns in the rule 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)

Original rule

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

Rule id: c2df8373-6698-4b23-9d77-8e7968bd69f0

Metadata

version1.0
classificationTLP:CLEAR

Tags:FILE