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  3. W32.Mytob.CF@mm


Risk Level 2: Low

May 15, 2005
February 13, 2007 12:38:50 PM
Also Known As:
Win32.Mytob.DA [Computer Assoc, Net-Worm.Win32.Mytob.t [Kasper, W32/Mytob.gen@MM [McAfee], W32/Mytob-EM [Sophos], WORM_MYTOB.EM [Trend Micro]
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

W32.Mytob.CF@mm is a mass-mailing worm that uses its own SMTP engine to send an email to addresses that it gathers from the compromised computer. The worm also opens a back door and spreads through the network by exploiting the Microsoft Windows DCOM RPC Interface Buffer Overrun Vulnerability (described in Microsoft Security Bulletin MS03-026) and the Microsoft Windows Local Security Authority Service Remote Buffer Overflow (as described in Microsoft Security Bulletin MS04-011).

Antivirus Protection Dates

  • Initial Rapid Release version May 15, 2005
  • Latest Rapid Release version May 15, 2005
  • Initial Daily Certified version May 15, 2005
  • Latest Daily Certified version May 15, 2005
  • Initial Weekly Certified release date May 16, 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: High
Note: On May 14, 2015, modifications will be made to the threat write-ups to streamline the content. The Threat Assessment section will no longer be published as this section is no longer relevant to today's threat landscape. The Risk Level will continue to be the main threat risk assessment indicator.
Writeup By: Kaoru Hayashi

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