Welcome to the Virus Encyclopedia of Panda Security.
|Effects: ||It infects files with the following extensions: COM, EXE, PAS and ASM.|
|Detection updated on:||June 8, 2001|
DieHard.4000.A is a virus that goes memory resident and infects all the executable files (with an EXE or COM extension) that are opened or run on the affected computer.
It also modifies files with ASM (assembler) and PAS (Pascal) extensions by inserting code in them for viewing messages, which overwrites the first 256 bytes of the original code. When they are compiled, they will display the following message: D1hex A5hex.
DieHard.4000.A is easy to recognize as:
When an application changes from command mode to graphics mode, the virus displays an animation that consists of the following two characters: S and W.
It denies access to files in write mode. When this happens, the virus displays the following error message in color: SW Error.