YARA · ESET malware-ioc

ESET_Apt_Windows_TA410_Flowcloud_Malicious_Dll_Antianalysis

Matches anti-analysis techniques used in TA410 FlowCloud hijacking DLL.

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

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

What this rule detects

Matches anti-analysis techniques used in TA410 FlowCloud hijacking DLL.

Targets: Windows PE.

It defines 1 patterns (0 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

apt-windows-ta410-flowcloud-malicious-dll-antianalysis.yarBSD 2-Clause License

rule ESET_Apt_Windows_TA410_Flowcloud_Malicious_Dll_Antianalysis : FILE
{
	meta:
		description = "Matches anti-analysis techniques used in TA410 FlowCloud hijacking DLL."
		author = "ESET Research"
		id = "b38a1d4d-5053-5a6d-be8c-c00261936417"
		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#L519-L552"
		license_url = "https://github.com/eset/malware-ioc/blob/17baf44964a77368e9149f4f593eb098beddf1c5/LICENSE"
		logic_hash = "8f14352118d32a43c17f70bd753acc48bd314965f10ab97818e8a434bbda96d9"
		score = 75
		quality = 80
		tags = "FILE"
		license = "BSD 2-Clause"
		version = "1"

	strings:
		$chunk_1 = {
            33 C0
            E8 ?? ?? ?? ??
            83 C0 10
            3D 00 00 00 80
            7D 01
            EB FF
            E0 50
            C3
        }

	condition:
		uint16( 0 ) == 0x5a4d and all of them
}

Strings (1 patterns)

Identifier	Type	Value	Modifiers
$chunk_1	hex	{ 33 C0 E8 ?? ?? ?? ?? 83 C0 10 3D 00 00 00 80 7D 01 EB FF E0 50 …

Condition

uint16( 0 ) == 0x5a4d and all of them

In plain words (Heuristic)

The file must start with “MZ” — a Windows executable (PE).
All patterns in the rule must match.

Test this rule in your browser

Drop a file to scan it with this rule using YARA-X compiled to WebAssembly. Nothing is uploaded.

Drop a file here or click to chooseScanned locally with YARA-X. Files up to 200 MB.

Open in editor

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: b38a1d4d-5053-5a6d-be8c-c00261936417

Metadata

version	1

Tags:FILE

ESET_Apt_Windows_Invisimole
APT / threat actorESET malware-ioc· ESET Research· 2021-05-17
ESET_Apt_Windows_Invisimole_CPL_Loader
APT / threat actorESET malware-ioc· ESET Research· 2021-05-17
ESET_Apt_Windows_Invisimole_DNS_Downloader
APT / threat actorESET malware-ioc· ESET Research· 2021-05-17
ESET_Apt_Windows_Invisimole_Logs
APT / threat actorESET malware-ioc· ESET Research· 2021-05-17
ESET_Apt_Windows_Invisimole_SFX_Dropper
APT / threat actorESET malware-ioc· ESET Research· 2021-05-17
ESET_Apt_Windows_TA410_Lookback_Decryption
APT / threat actorESET malware-ioc· ESET Research· 2021-10-12
ESET_Apt_Windows_TA410_Lookback_HTTP
APT / threat actorESET malware-ioc· ESET Research· 2021-10-12
ESET_Apt_Windows_TA410_Lookback_Loader
APT / threat actorESET malware-ioc· ESET Research· 2021-10-12