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  3. W32.Koobface.C


Risk Level 2: Low

July 15, 2009
July 15, 2009 4:23:00 PM
Infection Length:
24,576 bytes
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows Server 2008, Windows Vista, Windows XP
W32.Koobface.C is a worm that spreads through Twitter.

For more information, please see the following resources:
Koobface Turns the Other Cheek

Antivirus Protection Dates

  • Initial Rapid Release version July 15, 2009 revision 025
  • Latest Rapid Release version February 19, 2013 revision 016
  • Initial Daily Certified version July 15, 2009 revision 037
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 22, 2009
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: Easy


  • Damage Level: Medium
  • Payload: Opens a back door on the compromised computer.


  • Distribution Level: Medium
  • Target of Infection: Spreads through Twitter.
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: Ka Chun Leung & Kaoru Hayashi

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