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  3. Downloader.Fostrem


Risk Level 1: Very Low

July 5, 2009
July 6, 2009 7:06:52 AM
Also Known As:
Infection Length:
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows Server 2008, Windows Vista, Windows XP
CVE References:
Downloader.Fostrem is a Trojan horse that exploits the Microsoft Windows 'MPEG2TuneRequest' Object Remote Code Execution Vulnerability in order to download more malware on to the compromised computer.

Note: Virus definitions dated July 5, 2009 or earlier detect this threat as Downloader and Trojan Horse.

Antivirus Protection Dates

  • Initial Rapid Release version July 6, 2009 revision 038
  • Latest Rapid Release version February 19, 2013 revision 016
  • Initial Daily Certified version July 6, 2009 revision 004
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 8, 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: Low
  • Payload: Downloads more malware on to the compromised computer.


  • Distribution Level: Low
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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