YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_SUSP_JS_NPM_Sha1_Hulud_Nov25

Detects suspicious indicators for Sha1 Hulud worm

Suspicious / huntingSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X

Author: Marius Benthin
Date: 2025-11-24
Modified: 2025-12-15
Score / Quality: 70 / 85

What this rule detects

Detects suspicious indicators for Sha1 Hulud worm

It defines 2 patterns (2 text, 0 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

Download .yar

susp-js-npm-sha1-hulud-nov25.yarDetection Rule License 1.1

rule SIGNATURE_BASE_SUSP_JS_NPM_Sha1_Hulud_Nov25 : FILE
{
	meta:
		description = "Detects suspicious indicators for Sha1 Hulud worm"
		author = "Marius Benthin"
		id = "511fa6ca-25fe-57d4-a910-277c92d65e4a"
		date = "2025-11-24"
		modified = "2025-12-15"
		reference = "https://www.aikido.dev/blog/shai-hulud-strikes-again-hitting-zapier-ensdomains"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/mal_npm_supply_chain_nov25.yar#L25-L41"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "62ee164b9b306250c1172583f138c9614139264f889fa99614903c12755468d0"
		logic_hash = "95f7e657108bc63825f969baa28211c5c63746f525db5e71a486d76aaf98ba32"
		score = 70
		quality = 85
		tags = "FILE"

	strings:
		$x1 = "Sha1-Hulud:\\x"
		$x2 = "SHA1HULUD\"`"

	condition:
		filesize < 20MB and 1 of them
}

Strings (2 patterns)

Identifier	Type	Value	Modifiers
$x1	text	"Sha1-Hulud:\\x"
$x2	text	"SHA1HULUD\"`"

Condition

filesize < 20MB and 1 of them

In plain words (Heuristic)

The file must be smaller than 20MB (a cheap guard that skips large files).
At least 1 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://www.aikido.dev/blog/shai-hulud-strikes-again-hitting-zapier-ensdomains

Sample hashes

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

62ee164b9b306250c1172583f138c9614139264f889fa99614903c12755468d0

Licence & attribution

Author: Marius Benthin

Source repository: Signature Base (Florian Roth / Nextron) @ 94a1c48d7a

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: 511fa6ca-25fe-57d4-a910-277c92d65e4a

Tags:FILE

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