Virutas.gen is a virus that spreads to other computers by copying its code to other files or programs.
Virutas.gen does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.
Virutas.gen 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.
- Polymorphic: it encrypts itself in a different way with each infection it carries out. In order to do this, it uses different keys and operations. As a result, the virus has different characteristics in each new infection, which makes it difficult for antivirus pro-grams to detect this virus.
- Encrypted: it encrypts its code in order to make it difficult to detect. In order to carry out its infection, the virus decrypts itself and, once infection has been carried out, it encrypts itself again.
- EPO (Entry Point Obscuring): it infects programs that it allows to work as usual until a given point. Then, the virus takes control of the program and runs its own code.
- Cavity: it infects files without modifying their size or corrupting the data they contain, as it takes advantage of the cavities in these files to insert its code.