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SIGNATURE_BASE_MAL_Etoroloro_Malicious_Nodepackage_Dec25

Detects malicious component of node package named Etoroloro

MalwareSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Pezier Pierre-Henri
Date
2025-12-12
Modified
2026-05-15
Score / Quality
80 / 85

What this rule detects

Detects malicious component of node package named Etoroloro

Targets: Windows PE.

It defines 3 patterns (2 text, 1 hex, 0 regex).

Summary generated from the rule's metadata and condition.

Rule source

mal-etoroloro-malicious-nodepackage-dec25.yarDetection Rule License 1.1
rule SIGNATURE_BASE_MAL_Etoroloro_Malicious_Nodepackage_Dec25 : FILE
{
	meta:
		description = "Detects malicious component of node package named Etoroloro"
		author = "Pezier Pierre-Henri"
		id = "4c271502-68c6-5d20-85ea-c7f7628e417a"
		date = "2025-12-12"
		modified = "2026-05-15"
		reference = "Internal Research"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/mal_etoroloro_nodepackage_dec25.yar#L2-L27"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "f08c5b748c91dd45fd73c5e85920f656e361d94b869e2147410b2b528c6ae78f"
		logic_hash = "bd890359c38fb7f2af31390666691af70a202dcf352ef44e95493dc340c07e94"
		score = 80
		quality = 85
		tags = "FILE"

	strings:
		$s1 = "DLLSideload."
		$s2 = "Failed to expand path:" wide
		$op1 = {
         41 0f af c0           // imul    eax, r8d
         48 8d 52 01           // lea     rdx, [rdx+1]
         0f b6 c9              // movzx   ecx, cl
         45 69 c0 35 d4 04 00  // imul    r8d, 4D435h
         03 c1                 // add     eax, ecx
         0f b6 0a              // movzx   ecx, byte ptr [rdx]
         84 c9                 // test    cl, cl
         75 e5                 // jnz     short loc_1800022C0
      }

	condition:
		uint16( 0 ) == 0x5a4d and ( all of ( $s* ) or $op1 )
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$s1text"DLLSideload."
$s2text"Failed to expand path:"wide
$op1hex{ 41 0f af c0 // imul eax, r8d 48 8d 52 01 // lea rdx, [rdx+1] 0f b6 c9 // movzx ecx, cl …

Condition

uint16( 0 ) == 0x5a4d and ( all of ( $s* ) or $op1 )

In plain words (Heuristic)

  • The file must start with “MZ” — a Windows executable (PE).
  • All patterns in ( $s* ) must match.
  • Pattern $op1 must be present.

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Sample hashes

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

  • f08c5b748c91dd45fd73c5e85920f656e361d94b869e2147410b2b528c6ae78f

Licence & attribution

Author: Pezier Pierre-Henri

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: 4c271502-68c6-5d20-85ea-c7f7628e417a

Tags:FILE