Windows 2003/XP/2000/NT/ME/98/95

W32/Viking.OS is a virus that spreads to other computers by copying its code to other files or programs.

W32/Viking.OS uses the following propagation or distribution methods:

• Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
• Via Internet, exploiting remote vulnerabilities: attacking random IP addresses, in which it tries to insert a copy of itself by exploiting one or more vulnerabilities.
• Computer networks (mapped drives): it creates copies of itself in mapped drives.
• Computer networks (shared resources): it creates copies of itself in shared network resources to which it has access.

W32/Viking.OS uses the following infection strategies:

• Resident: once it has been run, the virus goes memory resident and stops functions belonging to the operating system. Therefore, every time the operating system or an application tries to access any of these functions, the virus will activate and infect new files.
• Prepending: it enters its code at the beginning of the file it infects. By doing this, it ensures that the virus is run every time the infected file is executed, but without interfering the functioning of the file.