A VIR file is any type of file that has been infected with a computer virus and has been renamed by an antivirus software program, such as Symantec's Norton AntiVirus or Avira AntiVir. The ".vir" extension is typically appended to the filename (i.e. program.exe → program.exe.vir) to indicate the file is a virus and to prevent it from being executed.

Removing the ".vir" extension may allow you to open the file, which may also enable the virus to run. Therefore, you should not open VIR files manually. Instead, it is best to let the antivirus program locate, quarantine, and remove VIR files.