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  3. W32.Sober.F@mm


Risk Level 2: Low

April 3, 2004
February 13, 2007 12:20:46 PM
Also Known As:
W32/Sober.f@MM [McAfee], Win32.Sober.F [Computer Associ, W32/Sober-F [Sophos], WORM_SOBER.F [Trend]
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP

As of April 11, 2004, due to a decrease in submission rate, Symantec Security Response has downgraded this threat from a Category 3 to a Category 2 rating.

W32.Sober.F@mm is a variant of W32.Sober.E@mm, which spreads itself as an email attachment.

The Subject: and Body: of the email vary and are written in German or English.

  • Symantec Consumer products that support the Worm Blocking functionality automatically detect this threat as it attempts to spread.
  • The worm does not have a static MD5 hash value.

W32.Sober.F@mm is written in Microsoft Visual Basic and is packed with UPX.

Antivirus Protection Dates

  • Initial Rapid Release version April 4, 2004
  • Latest Rapid Release version November 13, 2007 revision 038
  • Initial Daily Certified version April 4, 2004
  • Latest Daily Certified version January 15, 2008 revision 016
  • Initial Weekly Certified release date April 4, 2004
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment


  • Wild Level: Medium
  • Number of Infections: 50 - 999
  • Number of Sites: More than 10
  • Geographical Distribution: Low
  • Threat Containment: Easy
  • Removal: Moderate


  • Damage Level: Medium


  • Distribution Level: High
Writeup By: Kaoru Hayashi

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