YARA · ESET malware-ioc

ESET_Apt_Windows_TA410_Flowcloud_V4_Resources

Matches sequence of PE resource IDs found in TA410 FlowCloud version 4.1.3

APT / threat actorESET malware-iocBSD 2-Clause LicenseCompiles with YARA-X (with warnings)

Author: ESET Research
Date: 2021-10-12
Modified: 2022-04-27
Score / Quality: 75 / 80

What this rule detects

Matches sequence of PE resource IDs found in TA410 FlowCloud version 4.1.3

Targets: Windows PE.

It has no patterns: the condition alone decides (modules, file properties or other rules). YARA modules used: pe.

YARA-X says: warning[deprecated_field]: field `number_of_resources` is deprecated

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

Includes the imports needed to compile it on its own.

apt-windows-ta410-flowcloud-v4-resources.yarBSD 2-Clause License

import "pe"

rule ESET_Apt_Windows_TA410_Flowcloud_V4_Resources : FILE
{
	meta:
		description = "Matches sequence of PE resource IDs found in TA410 FlowCloud version 4.1.3"
		author = "ESET Research"
		id = "57b98823-439f-5a2c-a8cb-ac5e98953b06"
		date = "2021-10-12"
		modified = "2022-04-27"
		reference = "https://github.com/eset/malware-ioc/"
		source_url = "https://github.com/eset/malware-ioc/blob/17baf44964a77368e9149f4f593eb098beddf1c5/ta410/ta410.yar#L722-L741"
		license_url = "https://github.com/eset/malware-ioc/blob/17baf44964a77368e9149f4f593eb098beddf1c5/LICENSE"
		logic_hash = "7b475cfddb5f995f7e8e3293b8e6ae59a9e36143998bc444499b5dce467f8e9d"
		score = 75
		quality = 80
		tags = "FILE"
		license = "BSD 2-Clause"
		version = "1"

	condition:
		uint16( 0 ) == 0x5a4d and pe.number_of_resources >= 6 and for 5 resource in pe.resources : ( resource.type == 10 and resource.language == 1033 and ( resource.name_string == "1\x000\x000\x000\x000\x00" or resource.name_string == "1\x000\x000\x000\x001\x00" or resource.name_string == "1\x000\x000\x000\x002\x00" or resource.name_string == "1\x000\x000\x000\x003\x00" or resource.name_string == "1\x000\x000\x000\x004\x00" or resource.name_string == "1\x000\x000\x000\x005\x00" or resource.name_string == "1\x000\x001\x000\x000\x00" ) )
}

Condition

uint16( 0 ) == 0x5a4d and pe.number_of_resources >= 6 and for 5 resource in pe.resources : ( resource.type == 10 and resource.language == 1033 and ( resource.name_string == "1\x000\x000\x000\x000\x00" or resource.name_string == "1\x000\x000\x000\x001\x00" or resource.name_string == "1\x000\x000\x000\x002\x00" or resource.name_string == "1\x000\x000\x000\x003\x00" or resource.name_string == "1\x000\x000\x000\x004\x00" or resource.name_string == "1\x000\x000\x000\x005\x00" or resource.name_string == "1\x000\x001\x000\x000\x00" ) )

In plain words (Heuristic)

The file must start with “MZ” — a Windows executable (PE).
A for-loop checks a property over several matches or items.
Uses the pe module.
Uses the resource module.

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References

https://github.com/eset/malware-ioc/

Licence & attribution

Author: ESET Research

Source repository: ESET malware-ioc @ 17baf44964

Licence: BSD 2-Clause License (stated in the rule's own meta)

“BSD 2-Clause”

Original rule

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

Rule id: 57b98823-439f-5a2c-a8cb-ac5e98953b06

Metadata

version	1

Tags:FILE

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