vanish.com

Vanish DOS Virus activates whenever the 5th of the month falls on a Sunday, when it cycles each character on the screen down one ASCII value (B becomes A, 2 becomes 1, etc.) until every character has reached the ASCII value for the space character, effectively clearing the entire screen. The virus then allows you to continue computing normally.

1) Change the date to 5-5-91.

2) Open vanish.com

3) Everything will disappear in the screen, but it will recovered later.