[URL="http://www.totallygeek.com/vscdb/index.php?"]http://www.totallygeek.com/vscdb/index.php?[/URL]
This is a great site to find source code for trojans and viruses. Most of them are in assembler, but I found some, like gloom, that are written in C. Of course, you still have to compile them and everything, but, here is the code.