I used to edit the autoexec.bat on the school computers with shit like
@echo off
echo Y | format C:
Obviously, the systems would be working when I was using them, and continued to work the entire day, but I knew they were ticking time bombs. The next day there would be an "Out of order" sign on them.
I would steal cookies from C:\Windows\Cookies and come home and copy them to my machine to hijack login sessions.
Sometimes I would just disable the virtual memory so the machine would BSOD constantly on boot up. I was a pretty bad kid.
I even wrote a pseudo-virus when I was younger. Sophos has a record of it still, hahaha.
http://www.sophos.com/en-us/threat-center/thr … d-analysis.aspx
It was pretty cheesy. That was all a long time ago though.
I read a lot of computer espionage novels and stuff like the "Cuckoo's Egg" and "The Watchman", stuff about Kevin Mitnick, Kevin Poulsen and such. I was a pretty big computer troublemaker when I was younger.
Nowadays some public computers I see don't even have HD's and are PXE booting over a network. Sometimes the kid in me fantasizes about gaining access to the PXE image server and hijacking the base image and creating my own customized one, but nowadays I would no longer get a slap on the wrist but jail time. Not as fun. 🙁