Rock Steady
Nuke Info Journal [4]
August 1992
The Advantages of having a Memory Resident Virus, are unlimited. When our virus goes `TSR' it REALLY doesn't do ANYTHING. It just stays there, waiting to be called upon. the 80x86 really doesn't MULTITASK, so don't think the virus runs `in the Background' TSRs tend to hook on Interrupts, depending what function they must do. If it must be called upon OFTEN, hook Int 1C, if your must run when an File is Executed/Open/Close Hook Int 21h. And everytime Int 21h is called, Your Virus Runs FIRST, then it calls the original Int 21h.
I will try to explain on how cut off a block of Memory, Then we'll allocate memory for the Virus, change the program MCB, and move the virus resident in memory.