DIE -- HARD VIRUS

Information about the Die-hard virus:

This virus infects COM and EXE files under DOS. The virus stays in memory when an infected file is executed. When the virus is active in the memory, it will be infecting all the EXE and COM files opened or executed. The virus adds 4000 bytes while infecting the file. One peculiar characteristic of this virus is that it adds some code to all ASM or PAS source files opened.
Die-hard virus has a payload that triggers on a Tuesday if the date is 3rd, 11th, 15th or 28th. On the trigger day after infecting at least 13 files, Die-hard virus displays S and W characters all over the screen. This display only works if the display mode is switched to graphics.

Die-hard virus first appeared in 1994 and it is in the wild.

Other names of Die-hard virus:
This virus is also known as DH2.