When the virus is run, it infects the first uninfected DOS executable in the current directory. If there are no more files to infect in the current directory, then it would search for the parent directory for more files to infect.
The infection size varies in different files.
The virus would to change the display to 640x480, display a television-like snowy screen, and produce a high-frequency tone coming from the PC speaker.
On older systems, however, it would clear the screen or cause the screen to flicker, producing the high-frequency tone.