Saying “sup” with `net send`

I was working a tech conference, probably around 2001, with about a hundred PCs networked together. A colleague of mine intended to send a simple "net send" message to only my workstation, just as a joke. He messed up the syntax and the popup appeared on every PC in the conference, including the giant screen in the main conference hall. The message: "Fuck you". He was fired the next day.

(Don't feel bad for the guy. Getting fired was the best thing that ever happened to him. He was a weekend "action photographer" [surf/skate/snowboard/...] who decided to go full-time after losing his job. He rode the early-2000s "extreme sports" wave and ended up being quite successful, and more importantly, much happier.)

This brings back good memories from High School. Here's a bunch of things we used to do:

1. Set fun messages on all the HP Printers: https://www.irongeek.com/i.php?page=security/jetdirecthack

2. Bypass firewall restrictions by setting http:// to https:// (later had to resort to SSH tunneling using Putty). Got me banned from our library for a month when I was on Facebook and a teacher passed by.

3. Our student directory set a cookie to a 6 digit identifier in the cookie. We could access any student's grades and details by just setting it to another ID, or looking at their lunch card.

4. During finals we wouldn't be allowed to see our grades until after all the finals were submitted into our grading portal. Somebody picked up on the fact that if you stop the page load before it finished that the grades would show up. Using JS to block our grades after they loaded didn't stop even the least technical people.

5. Some of our labs had monitoring software to make sure we were working. We could just kill that process and they would lose access.

6. Invert MacOS screen colors using Control + Option + Command + 8. Teachers didn't know how to recover from this and would resort to restoring the entire Mac.

7. CTRL + ALT + Down to flip the Windows screens. Again caused issues for a lot of people who didn't know this shortcut.

What a bunch of troublemakers we were...

just wanted to say I enjoyed the alert() at the end

It was an absolute free for all when windows machines started to be plugged into campus networks.

The prankster's evolution generally went from net send to NetBus and then to Back Orifice in those days as the tools rapidly made such tomfoolery a point-and-click affair. Interestingly many of the features in these early Windows prankster/hacking tools heavily shaped modern day remote administration / MDM software. I actually remember BO being used as a proper remote management tool in some situations.

I was worried for them, glad it worked out. I wouldn't be so sure about this statement: "now that I’m a grownup I know that [...] we wouldn’t have gotten in very much trouble anyway."

Unfortunately this was the type of thing that would get students banned from the computers, or only allowed to actually use the computers on Friday to do their computer science work (like my friend Dave).

Speaking of NET SEND specifically, I went to a vendor for training once (circa 2000) and they mentioned someone who had recently come for training and was sent home because they had used NET SEND * there. I wonder what their employer thought of that.

Either me or a friend has at some point (in the 80s or 90s as minor students) been: kicked out of computer lab, had notes posted in the library that we are not to "hone our programming skills", kicked out of the Supercomputer Challenge[1], been told (second-hand) we're "a security risk" by the government, been put specifically under remote monitoring by the teacher, lectured, sent to the principle, had the police sent to their house, been told we "probably have an FBI record" and "are putting their parents' jobs at risk" over similar levels of playing around with computers that they let us use, not even trying to do anything particularly "hacker (cracker)"-like.

[1] https://supercomputingchallenge.org/22-23/index.php (Not this specific year obviously. More like 30 years ago.)

When I was in college I realized that they hadn't disabled net send with wildcards on the CS computer network. We all had individual logins.

One day I walk into my lab class and see that a poor soul forgot to logout of his session. I'm sitting with my lab group and explain this "net send *" macro that would send a message to every single account on the system.

Another person in my group says "I'll do it." He types it in and presses enter.

We log out of the account, then log into one of our accounts, see the message, laugh and move on.

The next week, I get to my lab and this kid walks in and says to my lab group member sitting in front of the computer "Can I speak to you outside?"

He goes outside and we think nothing of it, but then I hear my lab partner outside the door say in a raised tone "Look, I have no idea what you're talking about! Goodbye!" and he comes storming back in.

This lab partner was absent the week before and didn't know what had transpired. We ask, "What did that guy want?" He says, "Some BS about how he thinks I sent a message through his account to everyone on the network because he forgot to logout last week and now he's in trouble with the CS department because they think he did it."

Our jaws dropped and I think if he had spoken to anyone else in the group we probably would have laughed and he would have known it was us right away. I still wonder how much trouble he got in on our behalf for embarrassing the CS IT department. Didn't seem like that big a deal to me.

Had a similar experience in middle school. We started initially doing net-send to specific users and having played around a little bit with batch files/command prompt before I tried net send *.

Well the entire county was on the same network. All computers in the school district received my message. Fortunately the message was just "hi", and I think it was only sent once.

Like the OP, in retrospect I saw that the message shows the sending computer+user. Since we had student-specific logins it didn't take long before I was tracked down and reprimanded. I think they even told my parents about it and were threatening suspension etc. But at a certain point it became kind of obvious that the network/configuration was more at fault than a curious kid. So I got off with a stern warning and narrowly avoided a life of crime.

I did this prank, only it was more elaborate. We were in the lab, playing around with Windows NT (so all machines were set up with the same Administrator password), and one thing you could do, is to get a remote telnet, and `net send` to yourself, but on the remote machine, so the origin would basically be that person's machine, which makes it impossible to detect the actual sender.

Once the person was sufficiently annoyed, he disabled the Messenger service, but again, because all Administrator passwords were same, it was possible to just connect to the Services snap-in in Microsoft Management Console, and re-enable it, send the message, and immediately disable it, so once that person went to check - the service would be off...

In retrospect it was somewhat cruel, but oh well...

My entire school district was in the same domain/workgroup and so I remember sending a net send to literally every computer on the network, 4 high schools (mine had a population of 4K students), 3 middle schools and a dozen elementary schools. The IT department came running into the computer lab to figure out who had done it. I simply closed the window, switched back to MS Word and played dumb. Good times.

A few months later I got expelled for some Novell netware breakin shenanigans but that whole experience was well worth it. I had been booting into slax and stealing SAM files from shared/library computers and then cracking them at home with lophtcrack to figure out passwords. The top level system admin had a 5 letter dictionary word, “north” as his password. I had keys to the kingdom. I’d shut systems down all the time for fun but never broke a thing. They tried to throw the book at me but fortunately it all fizzled out in the end.

Exactly the same experience for me, and similar with the game too.

We figured out that while the C: drive wasn’t accessible in Explorer directly, you could create a desktop shortcut directly to subfolders. Installed a copy of Worms World Party on all of our machines using that; somehow, although the machines were imaged weekly, it ended up on the image and got copied across to every school computer which was convenient.

I also went a step further with the joke messages, creating a program which showed a bunch of dialogs with choices in a loop. It couldn’t be closed and some choices did things like open/close the CD tray (as a “diagnostic”). People started just dragging it to the corner of the screen out of sight.

We also had a self sign-up system for sports, where you could pick a main interschool sport, or a “development” sport that was more about learning interesting stuff. The system was pretty insecure, using your date of birth as a “password”, but it also turned out that it had an SQL injection, so I used that to set everyone’s sport to Equestrian. Getting to hear an announcement at the school assembly about how the computer system had a problem was pretty great. I even emailed them about the injection issue but they never fixed it. (A risky move, really.)

I worked for Microsoft during those times doing security for Windows.

In the early 90s employees still occasionally used the Messenger service (the service behind “net send”) for messaging. It was originally intended for alerts like print job completion or server powering down, but it became widely abused.

It could actually be used over the internet if the target machine was addressable, eg had a non-rfc1518 address.

We started getting lots of complaints about abuse in the mid 90s as the web was taking off, and changed our best practice recommendations to disable that service; it was not mission critical.

Most of the low level NetBIOS services were designed naively before people thought much about security; we eventually disabled or removed most of them.

This brings back memories.

My favorite discovery was that the "scheduled tasks" folder was shared on every computer in our school. This meant you could do the net send * bomb from a friend / enemies computer, and get them in trouble.

The other fun one was Borland C++ 6 had a limit on how wide the code window could be -- you could only horizontally scroll so far. However, you could hold down tab for a few seconds, then write something like cout<<"logout next time"; in their code. Unless you knew the trick, you'd never find the code afterwards -- you couldn't scroll to the right far enough due to the limitation of the viewing window.

That's pretty funny. I worked at a unix shop and occasionally got a kick out of things like the following, if I ever saw one of my buddies logged in at the same time as me:

echo 'Terminal overheating, please blow on screen' > /dev/tty0

I remember doing this during one of my first years of college. I would usually finish the lab assignments early, so I would poke around the computers and see what I could get into. I eventually discovered `net send` on the cli, and read through the help to discover that you could broadcast with a wildcard.

So, I promptly ran `net send * All your base are belong to us`.

The immediate result was giggles from all around the computer lab. As soon as I realized I had sent it to every computer in the lab, I realized I had no idea what other computers I had sent it to. I decided my best course of action was to log out of the machine and switch to another one.

About 5 minutes later, a couple people came into the lab, going straight to the machine I had sent the message from. They looked around, asked the room if anyone knew who was using the machine, got a bunch of noncommittal shrugs, shrugged themselves, and left.

A couple weeks later, the Messenger service was disabled across the campus. I found out from someone that the message had popped up on every machine on campus, interrupting presentations and leading to some slight confusion on the part of teachers all over.

Same experience as OP and others here in discovering this setting (also in middle school). While sitting next to a friend I jokingly typed out "net send * [our third friend's name]" intending it as a "haha wouldn't that be wild. OK let's delete this now" quip, but my friend reached over and hit ENTER, we ran away from the computer like it was radioactive, and later discovered it was sent school district wide. We had used a non-user specific account but cracked under the pressure of being grilled as the obvious suspects for any computer shenanigans at our school and being good friends with friend #3.

The third friend's father was LIVID that our friend's name was besmirched by being placed in the contents of the pop-up, later threatened me over the phone, and put pressure on the school to throw the book at us (fulfilling his promise to "TAKE THIS TO THE MAT!"). My friend and I were suspended for a day and banned from visiting the high school computer club for some weeks.

From the district IT perspective the middle school's punishment somewhat backfired because news of our suspension resulted in many more students across the district learning about the command, greatly increasing the # of incidents and becoming a district-wide. They weren't able to figure out how to turn it off for a year+ after. As a temporary measure they made the printer in the high school library print out the originating computer of every net send message, which often backed up printer and caused the HS librarians (my mom happened to be the head one lol) to have to remove these useless sheets from the printer all day.

0/10 would not recommend glob experimentation

I have very similar memories from my time in the computer labs at school. We also discovered `net send` and got it disabled a few weeks later.

The computers were really locked down to the point that they were annoying to use. Right click was disabled (at least in windows explorer?), among other things. One of my acquaintances wrote a program in visual basic called "Firstname Lastname's Computer Fixer" that was somehow able to disable many of the restrictions on the computer. I remember it was a pretty large window with lots of buttons though I can't remember what they were all supposed to do. After passing it around for a few months it was deleted from all our home folders and I found out that he was suspended for a week and banned from using computers. The computers got even more locked down. Oh well.

Heh. If you used the underlying windows api calls, you could spoof the sender. Something I discovered when I did just that, in the Windows 2000 days.

Combine it with a for loop and you could generously message everyone on the LAN with little effort.

There's a reason why everyone around me turned off the net service after a while...

Oh this brings back memories. I remember before NAT routers became a common thing for home broadband connections and when most households only had one PC - my local DSL provider was assigning IP addresses from one block of IPs in an area. So browsing through other people’s shared directories on windows NT or 98 machines was trivial. So many people had open shares. Including sending out NET SEND messages.

In High School, I wrote an app in Visual Basic that:

1. Scanned the network for all the teacher's computer names periodically

2. Randomly sent a benign message from one random teacher to another random teacher like, "Hey, want to go out later tonight"

3. Sat dormant over the summer in the computer lab that had our programming class and was programmed to become active when school was back in session in the fall.

Apparently the thing actually worked! When fall came around one of my friends reported to me that he overheard teachers talking about random messages on NETSEND.

I never got caught. Maybe now that I'm bragging about it, as a stupid hacker does, I'll finally get hauled off to the principals office.

It's fun to see how we had such similar experiences growing up. We pretty much did the same thing in high school with Net Send. Except we sent "All your base are belong to us" and then left the library computer lab in a real hurry once we saw the message go everywhere. Pretty sure it reached other schools too.

Congrats on topping HN with your blog's first post, lol.

This is something I actually worry about future generations missing. My core love of computers came from being able to tamper with them. Being able to poke around in the operating system, figure out how to do neat things, etc.

Today, students are given either an iPad or a Chromebook, and generally locked into using some horrific privacy nightmare like Gmail, and have very little ability to actually experiment with computers.

I suppose this means we have better security, but people like me born more recently may not end up in the field because of it.

We used to do this in high school all the time.

The other thing we did was access network shares which you could see, but if you tried clicking them in explorer they'd say "access denied". The administrator apparently didn't lock things down very hard so a two-line .bat file:

  @echo off
  net use Z: \\administrators

Would get us access to all sorts of crazy stuff.

Very funny! I guess is this more of a universal (tech) experience than I had realized: my friends and I spent a lot of time in high school griefing each other with `net send` (and the other `net`) commands.

My memory is fuzzy at this point, but I vaguely recall being able to change others' desktop backgrounds with a remote client. That produced a lot of entertainment value.

When our school started to provide network shares to students, they were pretty lax on security. I figured out that everyone's share was publicly read/writable, and the network path was pretty easy to guess. Whenever someone would annoy me I would replace a project file they were working on with some matter of nuisance program, like a zip bomb or a script that just kept opening word until the system ran out of ram. I'm surprised I never got caught, because I was too much of an idiot to properly cover my tracks.

I'll add to the chorus of people fondly remembering net send from their school days.

I seem to remember there was an option you could pass to override the sender's name so you could anonymize yourself and have the messages come from JESUS or MY BUM or something equally hilarious. You could even set it to the genuine ID of a nearby computer and watch the chaos unfold once the IT guy came running in.

I like to imagine there was some twinkly-eyed old trickster at Microsoft who saw to it that net send came enabled by default.

There was also a program that let you enable any disabled button in Windows by clicking on it. Turns out a lot of the security was only implemented at the GUI toolkit level.

There was something magical about those insecure school networks. It was amazing to watch how it affected the teachers, when you pulled some minor prank. They would flip out, not because you did anything particularly dangerous, but I guess just at the loss of control.

Good times.

Same series of events happened at my school.

1. Discover net send

2. Discover net send *

3. Get in trouble for using net send *

The next step was discovering telnet and the schools smtp server.

I remember doing this! I remember graduating to the more nefarious “Microsoft’s IPX implementation responds to broadcast pings”. It might have been this CVE: https://learn.microsoft.com/en-us/security-updates/securityb...

Luckily I went to a school that believed in redirecting the (endless) time and (boundless) energy of obnoxious nerds like me, and I spent far more time helping out than breaking things. Or at least I hope… the long tail on the IPX ping was pretty painful to stop.

Severals groups of boys at my grammar school† built what were called "User groups" which were "online" services accessible only on the school's computers with (at least theoretically) exclusive membership. There'd be maybe some simple games for your users, perhaps some sort of "bulletin board" and most often a "chat" service. Except, on the PCs we were increasingly using, these chat services all worked by using file I/O to a shared file, which is obviously very hard on the poor file server in ~1991 which is when this would have been happening. So the "chat services" were banned by staff. But I figured out how to write NetBIOS/NetBEUI software so I could implement chat without touching files, and this was allowed, increasing popularity of my User group, which I believe was named "Erewhon 2280".

† for Americans, the UK used to have selective education, some parts of the country still do, under this system children who test well at age 11 or 12 are sent to different state funded schools from their peers, mostly single sex such as a Grammar School, so that's a school of mostly high achieving all boys, this is probably a bad idea on net but it's popular for various reasons.

I think we've all done this to various effect. I made every computer (hundreds, maybe over 1000 on the domain) on campus go BEEP simultaneously. I almost didn't press enter, but I'm glad I did. When I heard the ubiquitous beep, the yelps from startled students in the rooms next door, and the sound of chairs as people jumped, I about lost it. I had tears coming out of my eyes. They never did figure out who did it.

All these people getting trouble for net sending are not going far enough.

When I was in school the admin left his account logged in and left the room. I was there to make few admin accounts to myself, and later programmed malware that worked as a keylogger and gave me some remote control of all the machines (I put it inside a .BAT script that was ran after login, distributing it to every computer in the school).

I used my powers by downloading stuff and burning it to CDs as I didn't have a good connection. I also gave some access to my friends, and the computer lab turned into a war zone. We were opening stuff on other people's screens, but not good stuff. Things like Goatse and people doing stuff with farm animals they shouldn't be doing..

After some time it had gone way too mad and computer lab got shut down. But the crazy thing is, after a while the school just let it go and didn't even notify our parents. Apparently, nobody wants to tell the parents that a room in school has been OnlyFans Farm Edition for a while.. I had some stern talks with the principal and IT teacher as the only suspect, but that was it.

Once upon a time we were pranking each other in the university lab. We thought ourselves pretty clever by convincing a friend to run a Fork Bomb.

"What is it supposed to do? Nothing's happening."

"Really? Did you run it in a shell?"

"Yeah, in my SSH session in the main server."

Oh.

The server was down for a couple of days while the admin figured out what happened, fixed it, and limited the number of open processes per user.

I had a friend that was very religious, he also had a blog about religion. Me and a friend of mine sent him a series of profanities via email through an open SMTP relay, that seemed like it was coming from one of the parish leader's account. I am very embarrassed now for doing that, but it was really funny in the moment.

I too discovered the wild card net send in high school. I was at an assigned computer in class though and ended up with a stern talk from IT in which they claimed I caused all sorts of network issues. I thought it was hooey at the time but I was pretty sheepish about the whole thing.

I didn’t get in trouble and returned to class.

Later that year I installed VNC server on my friends workstation in the same class and used it to mess with him during class. We had a pretty good laugh. Another friend saw this happen, took the idea with some of his friends and a few days later installed VNC server on a bunch of computers throughout the building. My understanding is they generally caused a bunch of chaos, it was figured out who had done it, and the group were arrested(!). They ended up with community service if I recall.

I very thankfully was not pulled into this at all and found out about the whole thing later.

I changed the environment variable PROMPT in DOS to "Enter Password:" once, confusing my teacher endlessly.

I recall in the late 80s on vt100's accessing BITNET allowed you to 'net send'-like to other BITNET nodes around the country. I used to randomly try to contact other users at other random educational institutions after using the 'finger' equivalent to remote BITNET sites. I can only imagine how my messaging probably messed up their terminal session screens and just end-user confusion ensuing.

Another 'write' unix shenanigans was the ability to send control sequences, so one could send a 'terminal reset' sequence to any user online a terminal room using a dumb terminal (wyse, vt100 etc) and it would quickly reset the terminal and log them off. One could even send a long sequence of control strings to force a crude ascii animation, then reset terminal if you wish. (not me of course)

I did: "net send * The server room is on fire, please turn off your computer!"

Not only that, but my computer name was assigned to my username so it said my full name next to it.....

I was called up to the office within 2 seconds and immediately suspended. I also got braces that dad. Rough day. :(

When your school's IT department realise you're doing this, and remove "Command Prompt" from the machine's whitelist, you definitely shouldn't create a file called "COMMAND.COM" and double-click it to get into the prompt again...

I don't quite recall how I did it but I have a similar story of ejecting disc trays across my HS and school district. something with novell iirc

This exact thing happened with me and my friends in high school, except the random kid who eagerly tried the wildcard net send command chose to write “hey you b**es”, got suspended a few days later, and the IT department never figured out how to disable it (or chose not to).

Later we’d find ourselves logging in to machines remotely to do similar things in order to make it harder to trace. We did this with ordinary windows tools.

We even disguised that we were inside a terminal by creating shortcuts to the command prompt that changed the font, colors, and even the application icon to make it look like we were just running notepad at a glance.

Exactly what we did with this devious set of tools I’m not at liberty to speak of ;)

The hidden copy of UT resonated deeply with me. We spent many hours playing Doom and Quake in the high school computer lab when the teacher was out of the room. Every time we were discovered we had to hide it somewhere else.

Oh the NT4.0 days. When we found out about the "*" feature, we spammed each other and everyone like crazy. A few days later the admin got very mad, as he found the domain controller showing hundreds of stupid messages that he had to dismiss one by one. It took him a few more days to figure out how to disable the messenger service. In the meantime someone found out that the sender and receiver displayed in the messagebox were actually included in the payload of the "protocol" and not verified by the receiver. So someone cobbled together a little tool that was even more fun.

I had fun with fork bombs on the VAX/VMS machine at uni. Till the day it ran too quickly for me to stop it. Walk of shame to the CSO to own up and for them to terminate the run-away processes on the Sysop console.

Someone at my school circa 2008 added a script to one of the startup folders such that whenever a student logged on, it would print the "ORLY Owl" on the default printer for the machine. This led to a lot of toner and paper purchases, and some very annoyed teachers. I had a bit of a reputation at the school for computer tomfoolery, so I was questioned, but I wasn't involved with this one. I do still have one of the print-outs taped to a board in my childhood bedroom though.

Reminds me of the day, obviously some years earlier, that a few of us aged about 10 years discovered *NOTIFY and even better, *REMOTE on the Econet connected Beebs we had at school.

Oh, here’s the manual (PDF), which we never read: http://chrisacorns.computinghistory.org.uk/docs/Acorn/Manual...

I wrote a net send script in high school that sent a pop up to every computer in the building… 500 times. Someone snitched on me. I regret nothing.

I'm late to comment, but wanted to chime in and add that this is how I was expelled from high school.

All of our computers among 50+ elementary/middle and high schools were networked together. We could open CD trays, turn on/off window services, force restarts and other things we thought were funny at the time.

One day, I decided to send the message 'I'm gonna kill you' to a friend and didn't know his computer name. I left the wildcard in there for the domain to our school and poof, 900+ computers got the message. Lots of kids were scared and jumped out of their seat reading the message. I realized quickly i made a mistake...

I was labeled for sending a terroristic threat and kicked out. After some litigation and staying at home for a few months, they let me back into school the next year.

Lots of memories, very similar experiences. Fun detail: net send * only broadcasts to machines in the same working group, and since we had classes where each student had their own machine and each class its own group, we could actually use it to broadcast messages to our class, and no one else. We also gave self-chosen names to our machines and used net send as a reasonably practical live chat system during classes.

I also told a friend in another school about the command, and their attempt also ended up sending a message to every machine in a district with over a dozen schools. We knew it would go to the whole school based on the group settings, we were still surprised that it went to other schools as well (still haven't really figured out how that worked). Luckily for them, nothing got disabled, and they kept using net send as a bilateral chat system happily ever after :)

we used to do similar with the Mac's ability to speak using the command 'say'. we'd ssh into a computer we knew someone to be sitting and have it 'say' something while using their name. at least, until one day, the 'say' app was not longer available!

I put `net send * Seniors2005` 200 times in a OPEN_ME.bat file and put it in our shared folder on the school network (it was buried deep in the Art department directories and was full of emulators and music and stuff.

My friend saw it and said "What's this?" I told him not to open it and of course he did so immediately.

This was a K-12 school, so every single lab, every single teachers computer all the way down to kindergarten got it.

When IT came to my friends machine, I fessed up and got in trouble. Banned from school computers for the rest of the year, all my teachers got a notice about it and I had more than one awkward conversation about what I did.

IIRC, you could do this by IP, also. I remember my best friend in college and I mapping out the addresses of all the computers in our main lab and using it to send messages between each other. Kept the map in a notebook so we always knew where to send to regardless of where we sat down. We also used it to troll the student in front of us who was looking at porn and playing games in the middle of class. It didn't get shut off until after we came back between semesters, so I don't think we ever explicitly got caught, other than network techs seeing someone was doing something.

This brings back memories of sneaking a C compiler onto a classroom computer in high school and writing a program which issued ten thousand net-sends to a bully's computer. IIRC, the next send window popped over every other window and it effectively denial of service attacked his UI. The options where to click thousands of times or restart the computer. Well, it was pretty easy to rerun the program once his was restarted and let's just say he didn't take it well. It was a blessing that net send doesn't show sender information.

In the time before CI servers, when I ran a lab of 'doze boxen, I'd use "net send" to alert the consoles we had for admins whenever there was an error a human needed to pay attention to. We'd decided that playing noises was too annoying. And because the test slav^H^H^H^Hagents were all on KVMs, it wasn't likely we'd see the screens of the ailing machines.

Once it was determined that "net send" was a security problem, thus forbidden, we found ways of alerting involving less spit and bailing wire. And fun.

What fun that was. My friends and I did something much more innocuous in high school and earned outselves a stern talking-to: we changed the IE/Netscape home page on half- a dozen lab computers to a Geocities/Angelfire site we'd made and on which we had been experimenting with JS. Nothing sinister or malicious, but enough to cause a bit of confusion for a few students. The school's admins ran a pretty tight ship policy-wise, but it was a veritable playground for "network-curious" sorts like myself.

Probably worth mentioning that, at a place I worked at in the XP era, we used net send in the way it was probably intended: to send short messages to other people on the same network. The same type of day-to-day stuff that is sent over Teams today. The * usage was known but not used often, and not outright abused (though it may have been overused, given the level of annoyance it could generate).

I always found the *nix 'talk' command much more annoying, since it would throw off the screen drawing for programs like pine.

Pretty funny seeing how many others did similar pranks. The best one we discovered was that the third party screen sharing / remote admin tool installed on every computer in every lab/classroom (high school) consisted of client.exe and server.exe, with no password, and while server.exe was not installed on the client machines, it was in a shared folder in at least one place on the network.

All that was required to "take over" any machine on the network was to open server.exe and enter the IP address

At university, we had a whole IM network built around "write" on a multiuser *nix server (over the past 20+ years, the university netsoc has run services on freebsd, solaris and various flavours of Linux). We also had terminal based maps which would allow you to find friends based on the IP they logged in from.

See https://c-hey.redbrick.dcu.ie/ for the wrapper around write. These days students seem to prefer discord. :/

Had 3.5 weeks of excel classes in school, completed everything in 2 days and spent the rest of the time playing quake or annoying the ones not finished with net send in loops. Now that I think about I'm not sure this classroom of computers were on their own broadcast network or not, but they were running an older version of windows that didn't block net send by default while others had a newer version.

Hah, never understood what that net send stuff was about. This is a typical example of rubber stamp semantics. You ask for an OS that can do basic stuff then comes with a bunch of obscure facilities that you don't know are security problems (in this case relatively harmless DoS but I'm sure I remember RCE vulns related to that subsystem) unless you are 0.001% of the population.

net send was the messenger of choice on the St. Petersburg State University campus back in the 00's. People called it “popup” (after the earlier WinPopup utility perhaps). I remember seeing some announcements (like about lost belongings or something) put up on a (physical!) bulletin board saying “message me on popup: [hostname]”

I also discovered net send in high school and abused it similarly for a brief time, but never knew it had wildcard support! wow

Oh man. This is so similar to my high school story. The only difference is instead of 'sup', one of my friends typed 'you can't catch me I'm the gingerbread man'.

Although, I don't actually think they really tried or were ever going to try to catch him.

Same thing for me, the feature was disabled shortly thereafter.

Ah the memories of innocence in computing :)

We had a computer lab that overlooked our library, which also had computers. It was fun to pick a specific computer and `net send` messages to that person that made it clear they were being watched. I sure hope we didn't cross any lines messing with people, but I really can't remember.

Had the same experience at my school, but IT was much slower. net send * worked for weeks if not months

many years ago I had a fortran class where our lab was a bunch of x-terminals connected to some old SunOS Sparc thing. all of the user sessions used ttys that for some reason were world writeable. anyone who has had the misfortune of writing fortran code will remember that its very column dependent. each line of code has to have certain elements lined up in the proper columns.

so, of course I wrote a little script that wrote a single space character to a random tty every so often. the character wouldn't be in the users source code but since it was shown on their terminal they would generally hit backspace to "fix" it which made the text on screen line up but misaligned the columns in their actual source file.

very few people got their assignments to compile

True story, a classmate of mine bounced a <pre>net send</pre> command off my workstation in highschool, and our incompetent sysadmin banned me from the computer lab after stealing my blue laser usb mouse. Sounds ridiculous but it's a true story.

lol my friends and I discovered the same thing in high school programming class. Except we put "net send *" in an infinite loop with the message "lol dicks". That day, we were heroes (and villains, to the extremely computer illiterate staff)

My high school also had a hidden copy of Unreal Tournament squirreled away on a network share somewhere, half of CS class always finished up with 20 minutes to spare to get in a few rounds. Good times.

Oh man I remember doing the exact same thing in high school, didn't think the wildcard would actually work. Overheard concerned teachers talking about it and never fessed up until now!

Totally worth reading until the very very end, loved the js alert :)

I got fired from a training placement in 98 for sending a NET SEND message to the internal Novell Netware 4.xx based mail server, stopped the mail for about 30 mins.

Oh goodness, what an awesome end. I love this article so much.

I can't get enough of these stories from the early days of computing. Perhaps I was just young, but those years felt magical to me.

Every kid was doing this back then also filling up CIFS mounts to blue screen entire labs or schools of machines was good times.

NET SEND was fun because it did true purpose of computer programs , amplify your communication and computation capability.

Oh yeah, I totally did this in high school in the early 90s -- but we never discovered *!

"We’d gone wall to wall sup!" hilarious.

Read to the end!

Yep, happened to me. Literally just sent 'Test'. Got yelled at by two people, but that's about it.

Haha, I got a great laugh at the end-of-article scroll. Well played!

The command that got me in trouble was shutdown /i

Ah, yes, back where network security was an oxymoron

Sorry, can’t resist the temptation: sup

Be sure to scroll to the bottom

great first post haha.

LUL Brilliant!

>When I was in junior high, my friends and I discovered that a Command Prompt command called net send was enabled on our school network

I knew some folks who did that as well. Unfortunately I was not in the set of folks who could get away with such nonsense. You were incredibly privileged, and need to be mindful of that for the rest of your life.