Vobfus
Overview
Vobfus (also known as Beebone) is a Windows worm. As documented by Malpedia (Fraunhofer FKIE), it searches for computers on a network and creates copies of itself in folders with open access; for the malware to activate, a user must first run it on the computer. Vobfus is written in the Visual Basic programming language and uses code obfuscation, which is a distinguishing feature of the family. This obfuscation complicates attempts by anti-virus software to analyze the malware. The Beebone botnet associated with Vobfus was the subject of a coordinated takedown.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1091 T1036.005 T1105 T1547.001 T1083
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1036.005: Monitor for executable files running from unusual paths or with deceptive names. Use EDR to detect process masquerading.
- T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
Generated Detections (Boilerplate)
These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.
YARA Rule
rule MALWARE_WIN_VOBFUS {
meta:
description = "Detects Vobfus (worm)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "vobfus" ascii wide nocase
$s2 = "win32.vobfus" ascii wide nocase
$s3 = "vobfus.a" ascii wide nocase
$s4 = "vobfus.b" ascii wide nocase
$s5 = "worm.vobfus" ascii wide nocase
$s6 = "bfus" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Vobfus Activity
id: 513e5152eff74b716e9bc33f02963458
status: experimental
description: Detects generic indicators of the vobfus malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*vobfus*"
- "*win32.vobfus*"
- "*vobfus.a*"
- "*vobfus.b*"
- "*worm.vobfus*"
- "*bfus*"
condition: selection
level: mediumReferences & External Analysis
- Malpedia (Fraunhofer FKIE): Vobfus (win.vobfus)
- Search "vobfus" on VirusTotal (External Analysis)
Frequently Asked Questions
What is Vobfus?
Vobfus, also known as Beebone, is a Windows worm. According to Malpedia, it spreads by searching for computers on a network and copying itself into folders with open access, allowing it to propagate to other machines and drives.
How does Vobfus spread?
Per Malpedia, Vobfus searches for computers on a network and creates copies of itself in folders with open access. For the malware to be activated, a user must first run the copied file on the computer, so it relies on a user executing the dropped copy.
What makes Vobfus hard to detect?
Malpedia notes that Vobfus is written in Visual Basic and uses code obfuscation, which is a distinguishing feature of the family. This obfuscation is designed to complicate attempts by anti-virus software to analyze the malware.
What is the connection between Vobfus and Beebone?
Beebone is another name for the Vobfus family. The Beebone botnet built on this malware was the subject of a coordinated takedown effort, as referenced in the Malpedia entry's cited reporting.
How do I remove the Vobfus Worm from Windows?
Manual removal of Vobfus is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Vobfus a virus or a Worm?
Vobfus is classified as a Worm. Unlike traditional viruses that infect files, modern malware like Vobfus typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Vobfus infection?
Symptoms of Vobfus can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Related Families (Category: worm)
Explore other malware families in the same category:
Protect Your Network Against Worms
Want to prevent Vobfus and similar threats from compromising your organization? Read our comprehensive defensive guide: Worm & Virus Protection.
Machine-readable
Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/vobfus.json
Ecosystem & Interactive Environments
This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.