W32.Perrun

W32.Perrun is a virus that appends itself to .jpeg or .txt files. The malicious content of files that it alters will not spread to other computers. Indications of infection are that .jpg or .txt files will have increased in size by approximately 11KB, and the presence of the file Extrk.exe or Textrk.exe.

The original data will not successfully extract from .jpeg files if the file C:\Windows\System\Shimgvw.dll does not exist on an infected computer.
The original data will not successfully extract from .txt files if the file C:\Windows\Notepad.exe does not exist on an infected computer.

Protection

• Initial Rapid Release version June 13, 2002
• Latest Rapid Release version July 12, 2008 revision 018
• Initial Daily Certified version October 31, 2007 revision 003
• Latest Daily Certified version July 12, 2008 revision 019
• Initial Weekly Certified release date June 19, 2002

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low

Distribution

• Distribution Level: Low