Hi,
I want to study abt how virus working.. like how it get into the memory and attaching itself to other files and replication part.

I gone through some of the articles in web but I'm able to find those articles are based on DOS. I knew writing memory resident prg and interrupt prg in DOS.
In dos there is no protection in memory and we can access anywhere in the memory. But how the virus working in win 2k/xp ?
I'm half the way studying winnt internals but i'm not able to match with programming.
Is there any good turtorial will explain with realted to win2k.

Dont suggest me any books.. finacially i am not in the position to buy any books.....If any online e-books/articles/tutorials plz let me know.
-lok.