zlacker

>>revico+(OP)
Reminds of me my school leaving prank. I rewrote the whole internet on my school's computers. Google's logo became "Leavers '08", Facebook became "Hatebook" and was red, YouTube only played videos of cats, amongst other things.

These were the days when nothing had SSL, so you could just intercept and rewrite traffic!

My only requirement was: do no actual damage

It was implemented as a Debian live CD that you could drop into any school computer. It would boot up, then Ettercap would MITM the whole network by spoofing the router. It routed all HTTP traffic via Squid and a custom ICAP server that did the actual rewriting. If you removed the live CDs, the network just went back to normal within a couple of minutes.

Routing the whole school's network through one old Pentium machine wouldn't work though, so I figured out a way of doing distributed load balancing: it would do the ARP spoofing slowly and randomly. So, as you added more machines, it would just magically balance between them.

It worked great for about an hour then whole network mysteriously stopped working for the rest of the day. I left all the live CDs in the computers as a calling card.

Sorry, school network admins.

>>bfirsh+zg
I don't think this happened.

>>blueda+Zz
I'm less skeptical. OP already mentioned that most things were not encrypted back then, so this was probably still in the days of transparent proxies, so OP could have "just" added one with some ARP spoofing. They were somewhat common in school and office networks, and like regular HTTP proxies (except the transparent ones had the traffic redirected forcefully to them) they essentially consumed HTTP requests and sent new ones out to The Internet. While mostly used for caching and blocking, it seems relatively simple to me that OP could have just replaced e.g. some stylesheets served back to the client.