File Infecting Viruses File infectors,
also known as parasitic viruses, operate in memory and usually
infect executable files with the following extensions: *.COM,
*.EXE, *.DRV, *.DLL, *.BIN, *.OVL, *.SYS. They activate every
time the infected file is executed by copying themselves into
other executable files and can remain in memory long after the
virus has activated. Thousands of different file infecting viruses
exist, but similar to boot sector viruses, the vast majority operate
in a DOS 16-bit environment. Some, however, have successfully
infected the Microsoft Windows, IBM OS/2, and Apple Computer Macintosh
environments.
Related Topics
Macro viruses
Boot Viruses
What is a Virus
