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YARA · Signature Base (Florian Roth / Nextron)

SIGNATURE_BASE_APT_Virtualizor_Compromise_Payload_Aug26

Detects java based payload used in a campaign against compromised hosting providers using Virtualizor software

APT / threat actorSignature Base (Florian Roth / Nextron)Detection Rule License 1.1Compiles with YARA-X
Author
Jonathan Peters (cod3nym)
Date
2026-08-31
Score / Quality
80 / 85

What this rule detects

Detects java based payload used in a campaign against compromised hosting providers using Virtualizor software

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

Summary generated from the rule's metadata and condition.

Rule source

Download .yar
apt-virtualizor-compromise-payload-aug26.yarDetection Rule License 1.1
rule SIGNATURE_BASE_APT_Virtualizor_Compromise_Payload_Aug26 : FILE
{
	meta:
		description = "Detects java based payload used in a campaign against compromised hosting providers using Virtualizor software"
		author = "Jonathan Peters (cod3nym)"
		id = "4e31e430-72a6-5ccf-ac4a-dd38c6d2fc0e"
		date = "2026-08-31"
		modified = "2026-08-31"
		reference = "https://lowendtalk.com/discussion/220625/urgent-virtualizor-compromised-31st-aug/p1"
		source_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/yara/apt_virtualizor_compromise_aug26.yar#L24-L40"
		license_url = "https://github.com/Neo23x0/signature-base/blob/94a1c48d7ab499879287ff611dfe7f9c56376030/LICENSE"
		hash = "b81a4e1fab9fc4e404d57224fe71e2c143aa93942bd46998789bdc944a7870c7"
		logic_hash = "068e6ed5391205f4b98f227085fb2770952342166ea59cd20e7cd157d88b4df3"
		score = 80
		quality = 85
		tags = "FILE"

	strings:
		$s1 = "net/ikvm/clientvds/stresser/methods/impl/l4/minecraft/protocollib/" ascii
		$s2 = "oshi/util/VirtualizationDetector" ascii
		$s3 = "META-INF/proguard/base.proUT" ascii

	condition:
		uint16( 0 ) == 0x4b50 and filesize < 20MB and all of them
}

Strings (3 patterns)

IdentifierTypeValueModifiers
$s1text"net/ikvm/clientvds/stresser/methods/impl/l4/minecraft/protocollib/"ascii
$s2text"oshi/util/VirtualizationDetector"ascii
$s3text"META-INF/proguard/base.proUT"ascii

Condition

uint16( 0 ) == 0x4b50 and filesize < 20MB and all of them

In plain words (Heuristic)

  • The file must start with “PK” — a ZIP archive (also Office Open XML, JAR, APK).
  • The file must be smaller than 20MB (a cheap guard that skips large files).
  • 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

Sample hashes

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

  • b81a4e1fab9fc4e404d57224fe71e2c143aa93942bd46998789bdc944a7870c7

Licence & attribution

Author: Jonathan Peters (cod3nym)

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: 4e31e430-72a6-5ccf-ac4a-dd38c6d2fc0e

Tags:FILE

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