1. /
  2. Security Response/
  3. W32.Mydoom.M@mm


Risk Level 2: Low

July 26, 2004
February 13, 2007 12:25:43 PM
Also Known As:
W32/Mydoom.o@MM [McAfee], W32/MyDoom-O [Sophos], WORM_MYDOOM.M [Trend Micro], Win32.Mydoom.O [Computer Assoc, I-Worm.Mydoom.m [Kaspersky], W32/Mydoom.N.worm [Panda]
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows XP

W32.Mydoom.M@mm is a mass-mailing worm that drops and executes a backdoor, detected as Backdoor.Zincite.A, that listens on TCP port 1034. The worm uses its own SMTP engine to send itself to email addresses it finds on the infected computer.

The email contains a spoofed From address, and the Subject and Body text will vary. The attachment name will also vary.

  • Symantec Consumer and Enterprise products that support Worm Blocking functionality automatically detect this threat as it attempts to spread.
  • Due to a decreased rate of submissions, Symantec Security Response has downgraded W32.Mydoom.M@mm from a Category 4 to a Category 3 as of July 28, 2004.
  • Due to a decreased rate of submissions, Symantec Security Response has downgraded W32.Mydoom.M@mm from a Category 3 to a Category 2 as of October 27, 2004.

W32.Mydoom.M@mm is packed with UPX.

Translations of this Document:
Given the time needed to translate documents into other languages, the translated versions of this document may vary in content if the English document was updated with new information during the translation process. The English document always contains the most up-to-date information.

Available translations:
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Antivirus Protection Dates

  • Initial Rapid Release version July 26, 2004
  • Latest Rapid Release version April 29, 2015 revision 024
  • Initial Daily Certified version July 26, 2004
  • Latest Daily Certified version April 29, 2015 revision 041
  • Initial Weekly Certified release date July 26, 2004
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment


  • Wild Level: Low
  • Number of Infections: More than 1000
  • Number of Sites: More than 10
  • 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: John Canavan

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