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  3. W32.Zotob.B


Risk Level 2: Low

August 14, 2005
February 13, 2007 12:43:23 PM
Also Known As:
CME-164, Zotob.B [F-Secure], Backdoor.Win32.IRCBot.et [Kasp, W32/Zotob.worm.b [McAfee], W32/Zotob-B [Sophos], WORM_ZOTOB.B [Trend Micro]
Systems Affected:
Windows 2000

W32.Zotob.B is a worm that spreads by exploiting Microsoft Windows Plug and Play Buffer Overflow Vulnerability (described in Microsoft Security Bulletin MS05-039)

  • Virus definitions version 70814p (extended version 8/14/2005 rev. 16) or higher are required to detect this risk.
  • While computers running Windows 95/98/Me/NT4/XP operating systems cannot be infected remotely, it is possible they could be infected if W32.Zotob.B is executed locally (although this is an unlikely occurrence). Vulnerable Windows 2000 computers could then be infected by the compromised computer.

August 15, 2005: Added link to removal tool.

Antivirus Protection Dates

  • Initial Rapid Release version August 14, 2005
  • Latest Rapid Release version August 2, 2008 revision 020
  • Initial Daily Certified version August 14, 2005
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date August 14, 2005
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment


  • Wild Level: Low
  • Number of Infections: 0 - 49
  • Number of Sites: 0 - 2
  • Geographical Distribution: Low
  • Threat Containment: Easy
  • Removal: Moderate


  • Damage Level: Medium


  • Distribution Level: Medium
Writeup By: Rodney Andres

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