These are dangerous memory resident parasitic encrypted viruses. They hook INT 21h and write themselves to the end of EXE files that are executed. Sometimes these viruses play a tune. They also display the message:
Be Careful. YEKE Controls Your Computer.
and then halt the computer.
Yeke.2425
Sometimes this virus erases the CMOS and the disk sectors, then it plays a tune and displays the message:
TERMINATOR 2
livesall
The Judgement Day has come!
Your system has been terminated.
It also overwrites the disk sectors with the program that displays while loading:
This system has been terminated.
