Direct action virus

Trend Micro PC-cillin

Direct action virus

A Direct Action virus loads itself into memory to infect other files and then unloads itself, while a companion virus acts to fool an executable file into executing from a .com file. For example, a companion virus might create a hidden pgm.com file so that when pgm command is executed, the fake pgm.com runs first. The .com file invokes its virus code before going on to start the real pgm.exe file.