Virus.DOS.1000Years is a dangerous memory resident parasitic virus on DOS.

There are 2 variants:

  • Virus.DOS.1000Years.791 (A and B)


When the virus is loaded into memory, it first displays the following:

Memory allocatesion error
Please try again

And then it hooks INT 21h to infect any DOS executable that is run. Also, the virus does not check whether a file is already infected so it would reinfect the file on loading, and it does not infect files that are smaller than itself.

1000Years.791.a contains bugs that it would crash the system when it is loaded into memory, debugging is required.

Memory usage

The following table shows the memory usage of the variants.

Variant Memory usage in bytes
1000Years.791.a ?
1000Years.791.b 1,216

Other details

The virus contains the internal text strings:

1000 Years....
It's a wonder if the Earth will survive 1000 years with Human
This program was written in the city of Stockholm (c) 1993
-=Lord Zer0=-