File infecting virus is one that infect executable files and having an extension .exe, .com, or .dll. and application programs. These viruses either overwrite or modify the content of executable files.
- When the infected files are executed, the virus gets activated and remains present in the main memory even after the execution of the file is over. When another file is executed, this virus attaches itself to the new file and thus another file gets infected.
- Acid rain, Enigma, Nemesis, Cascade, Crazy, Alien .298 etc.