Free Zotob.A Remover Tools and Manual Removal Checklist

Top 5 Zotob.A Removers Compared: Which Tool Cleans Best?Zotob.A is a Windows worm that first gained notoriety in 2005 for exploiting vulnerabilities in the Microsoft Plug and Play service (MS05-039). Although it’s an older threat, infections can still occur on unpatched legacy systems or machines running outdated software. Choosing the right removal tool matters: some utilities focus purely on detection and cleanup, others add network-level containment, and a few provide thorough post‑infection remediation and hardening. This article compares five top Zotob.A removal tools, explains how they work, and recommends the best option depending on your needs.

What Zotob.A does (brief overview)

Zotob.A spreads by exploiting a buffer‑overflow vulnerability in the Plug and Play service on Windows 2000 and early server versions that haven’t been patched. Once it infects a system it can:

• Create backdoors and open network ports.
• Drop additional components or malware.
• Modify system files and registry entries for persistence.
• Attempt to spread laterally across networks.

Given these behaviors, a good remover should not only delete the active worm file but also detect and clean persistence mechanisms, network artifacts, and any secondary payloads.

Evaluation criteria

Each tool below was evaluated on these factors:

• Detection accuracy for Zotob.A signatures and variants
• Ability to remove worm files and clean registry/startup artifacts
• Network remediation (blocking propagation, scanning networked hosts)
• Ease of use for non-experts and availability of manual removal guides
• Speed and resource usage
• Offline/portable use (important for infected machines)
• Post‑infection hardening or guidance

The five tools compared

Individual tool summaries

Malwarebytes Anti-Malware

Malwarebytes is widely used for removing worms, trojans, and unwanted programs. Its signature database historically included Zotob and many variants, and the scanner is effective at detecting active processes, dropped files, and common persistence locations. Malwarebytes offers a portable install and a user-friendly interface that makes it a good first step for most users.

Strengths: fast scans, strong UX, good cleanup and quarantine. Limitations: limited network containment features.

Microsoft Safety Scanner

Microsoft’s free Safety Scanner is a standalone executable updated with Microsoft’s malware signatures. Because Zotob exploited a Microsoft Windows vulnerability, Microsoft’s tools often include specific detections and removal steps. It’s simple to run and doesn’t require installation, which is convenient for infected machines.

Strengths: authoritative signatures, no install required. Limitations: not real-time protection; minimal network tools.

ESET Online Scanner

ESET’s online tool and full antivirus products have historically detected Zotob variants. The scanner’s heuristic engine is good at identifying suspicious behavior and rootkit components. ESET provides detailed logs and remediation options, useful for administrators inspecting multiple machines.

Strengths: strong heuristics, detailed logs. Limitations: may require reboots and additional cleanup steps.

Kaspersky Rescue Disk

Kaspersky Rescue Disk is a bootable ISO that runs outside the infected Windows environment, making it effective at removing persistent or protected threats that can hide from in‑OS scanners. Its virus definitions and disinfection engine are thorough, and running from a clean environment helps avoid reinfection during cleanup.

Strengths: offline bootable environment, thorough removal of stubborn files. Limitations: requires reboot and some comfort with creating boot media.

Symantec (Norton) Power Eraser

Norton Power Eraser is designed for aggressive cleanup of malware and will flag deeply embedded threats. It can detect and remove unusual persistence mechanisms but can sometimes produce false positives, so review recommended removals carefully.

Strengths: aggressive detection for hard‑to‑remove items. Limitations: higher chance of false positives; better for advanced users.

Recommended workflows

• Home user, single PC: Start with Malwarebytes for a quick scan and cleanup. Follow with Microsoft Safety Scanner for confirmation.
• Admin on a small network: Use ESET or Malwarebytes to scan endpoints; if multiple hosts are suspected, isolate affected machines and run scans from removable media.
• Infected server or stubborn infection: Boot from Kaspersky Rescue Disk to scan offline and remove persistent components, then patch the OS (MS05‑039) immediately.
• When deep, suspicious persistence is suspected: Run Symantec Power Eraser for aggressive cleanup, but review each detection before removal.

Post‑removal steps

• Patch affected Windows systems (install MS05‑039 and subsequent updates).
• Reset credentials for accounts used on infected machines.
• Check firewall/router logs and block known malicious IPs if present.
• Re-scan networked hosts and quarantine infected systems.
• Restore from clean backups if system integrity remains uncertain.

Final verdict

• Best for ease of use and general cleanup: Malwarebytes Anti‑Malware.
• Best for offline stubborn infections: Kaspersky Rescue Disk.
• Best for aggressive deep cleanup: Symantec Power Eraser.
• Use Microsoft Safety Scanner as a trusted second opinion and ESET for detailed enterprise logging.

Choose based on context: for most users start with Malwarebytes, for servers or locked files use a bootable rescue disk.