IT removed games. I put them back in, but renamed the games, as well as the folder that they were hidden in. Then told people that I was sworn to secrecy BUT, and how to get into the games. I knew that I won when I caught a couple instructors playing it.

10 FOR X = 1 TO 20000
20 FOR Y = 1 TO 20000
30 NEXT Y
40 NEXT X
50 BEEP
60 GOTO 50

Nice try, FBI guy. We are not divulging any of our past felonies.

Edit: oh boy, was I wrong...

"Net send" message to every windows PC in the school. IT was not happy about that. Guess they should've disabled that exploit. I think it was before windows xp had (SP2?) disabled it by default.

Back in college, the old AppleTalk protocol did auto-discovery, so you could open up the Chooser and see virtually all of the Macs on campus. A lot of people didn't understand network security, or were lazy, so they'd share their drives with guest access.

This was way too easy, so for maximum deviousness and WTF'ery, I'd just make edits to a file here and there.

A teaching seminar was held in one of the classrooms that I took a class in. Students came in the next morning to see a username and password on the whiteboard. It didn't take long for us to test it on school computers.

The account had admin level access and could go into any student's directory. This led to rampant cheating on homework and labs.

I used it on my physics labs in senior year. I, and a few others, were caught and had to make up a few of the labs in the early morning in order to be able to take our finals. Also had detention for weeks.

A year later, after I had graduated and was in college for CS, I applied for a job at the school as a system administrator. The guidance counselor was in the room when I was talking to the IT admin. When I left, she brought up how I had broken policy and accessed files via that breach. The IT admin found me in the hall and asked me about it. I explained that I had taken my punishment, made up the labs, and didn't feel that it would affect my work at the school, but would withdraw my application anyway.

I taught to 2-3 naughty friends how to wipe something in the C:\ drive, some windows folder or something like that, and they did it in some Pentium PCs.

The teachers started looking PC by PC without knowing wtf was going on in the middle of the class.

They spent a few afternoon doing kind of community work at the college as punishment.

One of the kids in my computer class found out about netmsg and some of us started sending messages to each other. One day I saw a kid fell asleep at his desk, so I messaged him "wake up". It must have spooked him because when he woke up he called the teacher over and they puzzled over it together for a minute. I thought for sure since the name of the computer was in the message box and printed on a label on the computer that they would find out it was me, but nope lol

Another time in the same class I figured out how to create a local account so I could change the theme (it was Windows XP) to one I liked more. The teacher saw it when she was walking by and thought something was wrong with the monitor.

I found a blue screen of death screensaver online and I installed it on all the school library computers back my my freshman year.

Someone in my programming class told us how unplugging (and replugging) the Ethernet cable at a specific time when logging in gave us full network access. I didn't so much "mess with the computers" as "cheat my ass off, because I had access to all teachers' files."

I used them as a sort of thin client into a system that I had root on, so I could do whatever Science demanded of me without asking for access. Permitted, but certainly unexpected!

I would carry a USB stick that just had a VNC client on it. My home server was built from high-end scrap, and was leagues faster than anything the department had at the time, at least for student use.

I also had a Sharp Zaurus I had jury-rigged WiFi into, so I could run data analysis whenever I thought of something. It ran VNC or SSH. This was in the early days before it was called "machine learning" or even "big data". So we take this sort of thing for granted now (hello Google Cloud), but at the time it was magic superpowers to have immediate access to a machine with 4 physical CPUs from a handheld device.

Does writing an infinitely looping stream of 1s and 0s program on my math teachers ti-84 count?

She didnt know how to stop the program so she took the batteries out

Booted Macs into single-user mode and set a root password, then logging in with ssh from across the room and killing stuff that other people were running.

Had a class that was just taking old computer parts and building working systems. Installed SubSeven on some classmates’ systems and did shenanigans. Came in handy while we played Starsiege Tribes.

All mac computer lab (rev a/b iMacs), locked down with foolproof. No problem; bring a zip drive and boot from it by holding down option at startup. Use resedit to edit the extension for foolproof and remove all its resources. Extension no longer works.

Reboot into a completely unrestricted finder. Good times.

For 5th and 6th period in middle school, in the early 90s, I was in the same lab and had complete access to the computers. Rather, I was in charge of them. I was a TA for one period and it was a free elective for another period. I don't remember the details...but somehow I was there for both periods every day.

The teacher who ran the lab just left it all up to me. So, I installed games on all of the computers. Oregon Trail, DOOM, and Q*bert were the three that I remember.

Students would be sent up to the computer lab, on a daily basis for both periods. A lot of times the teacher who ran it would go run errands since I had it covered. When those kids came up, the entire lab just played games.

Also, since it was 6th period, I'd have the honor of shutting down the entire school network and systems at the end of the day. I'd get to call teachers and tell them to get off so I could shut it down. Some times I wouldn't contact them, and I'd just kick them off the network and shut down anyway.

It was a fun time.

I don't remember this exactly but when I was around 10 years old (circa 2007), me and my friends were playing around this ".bat" file that you create using notepad with a specific line which I forgot but essentially restarts your PC when you run the bat file.

We had some laughs during computer class.

During student council meeting, I had the chance to use the teacher/advisor's PC and of course tried this .bat thing for some laughs. Unfortunately this PC was older or something because when I ran the .bat file it didn't just restart the PC but ran into a significant error (I think some important files got deleted). Good thing no one noticed I tinkered with the PC, because the teacher was flustered.

Make a forkbomb on classmates computers and run it.

Using WOL to turn them on; fakeupdate.net; using open-airplay to mess with AppleTVs; rotating the screen 180° with Ctrl+Alt+Arrows or sth; sending deauth requests to access points with teacher's MAC addresses

I graduated high school in 1996 so internet access at school wasn't really a thing at that point. It was planned to be introduced in the next year.

ITT: people admitting to violations of 18 USC 1030, which is a terrible law that is way too vague.

We could unscrew the chassis of the computer and take whatever hardware we wanted to lol. We never actually got anything but we'd remove the RAM or unplug a hard drive and put it back.

We also found games hidden in certain directories. I even saw someone playing Undertale.

I also found a torrent client running on start up on one of the desktops seeding some movies.

If it counts, we used a program to throttle other devices' WiFi speeds. I forgot what it was called.

So many comments are about such major things, where as at most I only really put ThePowderToy into the shared drive for student accounts in my junior year of highschool and once in my freshman year made a simple batch program that all it did was constantly open up command prompts but didn't do anything harmful.

Y'all did so much more interesting and worse things than I did, I swear

I modified the installer for GeforceNow so It wouldn't require any admin rights to be installed. I was playing a lot of Overwatch during class after that.

We sent the shutdown command to each others. Next computer class, the command was disabled.

I was in our schools computer service team and they trusted the (competent) students way too much. I never misused those credentials but thinking about it now I could have done some hilarious stuff... Anyway. Even without too many permissions I did a thing or two to the computers. I once realised no computer had the BIOS password set. So I set one on a library computer to reserve it for me. Another time i realised you could take the whole network down if you connected two LAN ports directly with each other. That one was more on accident.

Learned the default account password and figured out which teachers had not changed their password from the default. Learned that all teachers had access to a share drive with all student records. Read through a lot of information.

Did not look at porn on school computers, because wtf?

At grad event, in front of elderly relatives, was called out for looking at porn on the school computers, other student was credited for breaking into all systems. More pissed about the latter.

Idk how much it's really messing with the computers, but once during a standardised maths exam where everything was supposed to be locked down oh all the computers (including preventing you from accessing the calculator), I figured out how to get around that and open the calculator (can't remember exactly how), but anyway I was good at maths so I didn't need it and I thought it would be funny to point it out to the teacher watching over the exam and I got accused of cheating so that was fun

Swapped the 300 MHz Pentium III for my 233 MHz Pentium II. The computer was very unhappy with this situation. Mine loved it, and I ran it all the way to 2006.

SubSeven

I remember dialing into the college network during the summer to access Usenet and play muds. It was some kind unsecured number, I forget how I found it

I don't remember messing with the computers thenselves, but I do remember my friends and I finding the password to the public wifi and connecting to it for all of like a day (w/ a VPN so as to not get caught) before getting booted off and the password reset. Rinse and releat a couple times before we couldn't crack it anymore

I didn't start it but I a shared directory for classes there was a folder nested deep into our programming classes folder that had Minecraft and a bunch of memes about the teachers, was a good time until it was found and removed

Seti@home, but if I did it today, it'd be folding@home. Also would boot to a linux live CD and play the one or two games that were on there. Apparently booting a live CD broke the "you cant install any software" rule the school had, so I had to stop.

As a rule I never cheated. But I was a in a very tedious typing course and could already type 60 WPM. So instead of doing all the exercises I edited the user files to make it look like I did well (but not perfect) on my assignments.

One time we got around the security for a shared windows folder (Win98). Another time a couple of us printed fake midterms for ourselves on official headered paper. But the one that sticks out is this trojan program I got from my older brother called deepthroat. I put it on a couple of other people's computers that I wanted to mess with, and proceeded to open their cd tray, pop up fake warnings/errors, and other random stuff that a friend and I thought was hilarious at the time. It all stopped when I popped up a message that said "Contacting [name]'s parents..." on this girls computer and she got the teacher's attention about it. He knew what was up and scanned all the computers. He was mad but we didn't really get in trouble. We also did the fake desktop screenshot stuff :D

Every computer had passworded but active local administrator account, so I think I went with the "how to reset forgotten password" (win7) and arrived to Trinity Rescue Kit, burned it to CD and went on with rebooting and cracking, I didn't have the balls to change the admin pass to my own, just left it empty.

Even got some good snacks for unlocking others assigned computers so that they could install whatever they wanted, mostly counter strike.

"Bypassed" their proxy, downloaded roms and ran emulators. They weren't very happy about that, said I "hacked" them by going to websites their stupid proxy didn't block. I found the logon prompt for the school server, tried to login with my regular credentials, they said I was trying to change my (already good) grades. Oh and ran Linux from USB drives sometimes but they never brought that up.

Our school computer lab had Mac LC II computers. On them they installed a software called "Foolproof" which would prevent users from making any changes to the system outside of specific directories, iirc. I realized it was a system extension by reading the helpfiles on the computer, and that you could disable all extensions by rebooting and holding the shit key on startup.

The guy who ran the computer lab was not too happy that a 10 year old figured all this out.