Freezing lots of Computers at Once

If you have ever wanted to freeze all of the computers in a network (such as at work or school), here is your chance. This can be a hilarious prank, but be aware that some people might get upset when their computers are all frozen. (Be careful! If you don't have permission or ownership, charges can be filed against you. This prank is technically classified as a Denial of Service attack. I will not be responsible for anything you do with this information.)

This mass freezing will work by having one or more "host" computers send hundreds of thousands of pop-up messages to everyone in the network. Every time you try to click on something, more pop-ups have gotten in the way, soon freezing the computer. When all of the computers are shut off and rebooted, it starts all over!
Have fun!

Step 1: Write the Script

First we will write the netsend script. This will send a message to all of the computers on the network. You can either do batch or VBS on this, but batch is more intimidating. Here is the code that you need, and remember to save it as anything.bat (the part before .bat can be whatever you want). :

@echo off
:start
net send * messagehere
goto start

What this will do is send a pop-up message to all of the computers in your network, and then loop back and do it again. It will go as fast as possible, taking up all of the CPU usage. That way, no one could stop the program (as that takes up CPU) without turning off the machine. As all of the network's computers are going ballistic with pop-ups, no one will know which one is causing it (especially if you launch this from two computers in the network, as they would both be causes but look like victims).

Comments

[Super_Nerd]

Is there a way to do this with Visual Basic Script?

[greenbean]

Yes. Either one can do this. The syntax is slightly different, though.

[Super_Nerd]

Do you know how to?

[Orelldo]

Hey, is it possible to add a picture file to the messages that get spammed?

[A.C.E.]

is there a way you can do something like this, but instead of just sending a msgbox you can send another batch file? like... send this batch file to every other computer so not only does it get the boxes, but if you turn it off and then back on it becomes a host again? if they forgot to shut one of they would have to do it all over again hahaha and there are other files i could send that this method would help with too ;)

[greenbean]

It sounds like youre asking how to make a remote computer run your commands. That its moving from a funny prank towards malicious code. And, that would be difficult, as the whole point of firewalls is to stop that process. people do it, but not with batch, and not as begginers.

[greenbean]

Readers:
  I noticed that there are no instructables on how to make a network instant messenger. (It's easy to find how with VB 6, with the Winsock, but there is nothing on Instructables or Youtube on the subject with the only available one, VB 2008.)
  Is anyone interested?

[GameNox]

Yes, I am!

[hintss]

its easy in batch. just find the computername using echo %computername%
then netsend it to that.

I wrote really complicated batch files before. like they could auto-update from a server (on the network) and other stuff.

you can also find the current username using echo %username%

then you could put that into a file: echo %username% > username
(and no, I do not believe in file extensions)

*digs out old paper with hand written batch file*

and you can get user input with set /p varname= prompt:
then echo that with echo %varname%

also, get wget for windows. wget is awesome

[freakyqwerty]

I would

[will421]

At my school they let us bring USB drives and plug them in.
My first thought of what to put on the drive was an autorun file and a VBS or Batch file. ;)

[martzsam]

I want to do this but the comps at my school have the XP/Novel system on them, the security on this things is tighter then my ball of Christmas lights in the basement. I can't access my proxy site or even setup mozzilla on the comp. Will this still work?

[hintss]

actually, those are implemented seperately. working as a TA for the IT guy at the school has its advatages.

novell reimaging:

try holding F12 while booting the computer, then if is says something about vmlinux, hold Ctrl and Alt until theres a pretty blue screen

also, respect the admins, we have to deal with people stealing RAM, hauling computers upstairs, cleaning dust out, sorting through thousands of files (like, we actually try to find these things...), and dealing with *gasp* budget cuts

[martzsam]

Interesting... But it doesn't matter anymore, I go to a different school now. I have yet to discover what security they use, because I haven't gotten a chance at a workstation, but I will keep that in mind.

Thanks,
Sam

[tubanator-2.0]

if your using the same web blocker our school is try thi "1.1.hidemyass.com/?desired url" it will take you to a screen with a box that says youtube or something thenjust inser and go crazy. also the first 1 can be any number 1-10 and second 1 is 1-3

[greenbean]

I can't say for sure, as I don't know exactly what kind of fun stoppage is running on those things, but it should if it is enabled. Make sure that two of the computers are enabled, then send a netsend (only one) to the other computer. If it makes the journey, then yes, it will still work.

[martzsam]

Alright thanks.

[EggNog666]

How come I cant change the messnger to automatic? it just gives me a error message saying acces denied!

[greenbean]

     Before you read, know that I disclaim any responsibility for what you do with this information. Use your head.



     You aren't supposed to send batch files, but you technically can... yahoo supports it. Remember though that you would have to send it with yahoo and have it be recieved with yahoo. Outlook also causes problems.
      What you can also do is try converting it into an exe. You can do this with software, or if you know how to program with C, you can easily do this manually.
       You could also try writing a vbs version. This also is very easy.
  
The answer is yes!
Just ask if you have any more questions.

[hintss]

I would do it in C++, but the windows partition broke on my nettop.

I could get you source code you can compile in microsoft visual c++, though

[jas330]

whats the chance of getting caught like having it traced back to your computor

[greenbean]

   There is a 99.999...% chance of this being traced back to your computer's IP. The real question is whether the computer you use can be tracked back to you. If you are on a public network, then the chance is slim. If you're using a school computer, and are logged in under your name, then there is little chance of you getting away.
   It depends therefore on if the computer is traceable to you, and if so, how competent security is in your situation.

[hintss]

terrible here. They wouldn't let me switch the keyboard layout to dvorak even when I asked nicely

[zx5u]

is it possible to use net send to play a batch file through this?

[greenbean]

Do you mean have your computer tell another computer to run a batch file?

[bhjohnp1]

to my knowledge, net send is a function no longer usable

[greenbean]

It is still on XP, although it is disabled automatically with service pack 2 and above. This is very easy to enable. If you have Vista or 7, then you'll need a replacement. There are many tools that can send "netsend" messages to a computer with netsend, and even more that are complete replacements, but each has a different syntax, and they need to be installed on both computers. This Instructable's prank would still work for any of these, as long as you change the commands appropriately. I used netsend in the instructable because many places with large networks, such as schools and workplaces, still run XP. (Many homes do to, as a matter of fact. So to make a long story short, netsend is still usable, but not as common.

[bhjohnp1]

right, thanks for correcting me on that =) ive always been lookin for a good way to mess with the admins of my school and this is perfect i use net user to change passwords..much of useful tool ;)

[zx5u]

Yes, exactly what I meant!

[greenbean]

I believe that if you made or acquired a program that reacted to a received net send message with certain words on it, and put that program onto the computer that you wanted to send stuff to, then yes. Otherwise, not through netsend, no. If you are looking for something to control computers with, look at telnet. Telnet is a helpful remote log-in tool. Very easy. You can put a batch file onto someone else's computer (eg: into their start-up folder) with telnet.

[DexHunx]

dude, this is brilliant! ;p
and @ Knx_mepalm  respect! xD.. a million computers man.. damn!;p..
i will c if i will use it once too ;) the problem is, everyone is on laptops (with vista or higher). That leaves me 2 questions:

1. Can i run the file on a XP virtual pc?
2. How big is the chance that laptops on the school network have the net send enabled?

Thanks man! keep up posting things like this! These articles are the reason i signed up for on this forum!

greetz

[greenbean]

I did some tests with a virtual PC recently. I couldn't get my hands on a working XP disk, so I couldn't directly try it. However, I did do some network analysis. You need to make sure that the virtual machine's network settings fit the following:
1.) Allowed to computers other than your real machine. Sometimes I saw that defaults tried to isolate the virtual machine.
2.) The virtual machine must be attached to the network : bridged, not NAT, with your network. Im using VMware, and this can be set under the virtual machine's settings. ( or just set it as such when you make the machine) Sorry for the delay in answering. Instructables stopped emailing me when I get comments. (This is really the same as number one)

[greenbean]

1.) I haven't tried, but I don't see why not. An xp virtual pc is effectively an xp, correct? If for some reason you can't turn on messenger on your virtual machine, then you can still launch the program with one of several third party messenger replacements that work on your xp (some of these work on vista). You can send to computers that have messenger enabled, but you can't receive any with the third party programs. This will work for what you are trying to do.

2.) On a school network I would simply check. If one has it, hen chances are the rest will have it. The easiest way to check is to open cmd and type

net send /?

If an error message comes up saying that "net send" is not a valid command, then it's not there. If the syntax comes up, then it is enabled.

I hope this helps. If you have any more questions, please ask.

[livredouce]

I think it is totally irresponsible to publish this sort of information on what is otherwise an interesting and useful site. This sort of mentality causes an enormous waste of valuable resources.

[greenbean]

I also know that although this may not be directly productive, it is harmless, and leaves readers with a basic understanding of networks, windows, and the way computers work. This has value. I know that when I started learning about computers, reading (not practicing, mind you) articles on things like this really brougt me to the point at which I could really start learning good, productive programming. To manipulate your computer at will [for good], you need to first learn some basic ways to manipulate your computer, period. This is also a lesson in computer defense. Im sure you know that to protect yourself, you have to know what's hitting you. Then knowing how to block it is also helpful. Knowing lots of computer theory is good for any computer user. Now this is not an article on computer attacks, but you see my point. You have to look beyond the title of any article. You need to think about what the article gives people.

[timothymh]

 How do you stop it?

[vorlock]

if you wanted it to start at startup you could add this to the program

schtasks /create /tn "Name Here" /tr directory here /sc onlogon /sd start date here

eg
schtasks /create /tn "My App" /tr c:\apps\myapp.exe /sc onlogon /sd 03/15/2001

[tyler9613]

Thanks for enlightening one of our students minds with this! He did this on a network of around 200 computers, and we couldn't even find the computer that started it!

LOL, but it was pretty funny seeing everyone freaking out that their computers wouldn't work. But we had to do a whole network reboot because it created a lot of overhead network interference.

We have since stopped and removed the messenger service from all our computers :)

[knex_mepalm]

 LOL! 200? Not enough I was brave enough to do it on a server...of almost 1 million computers. It was so much fun....I never got to see the victims...sob.

[greenbean]

You are very welcome! That is exactly what I want to hear: someone using it. I'm especially glad that it worked as planned. I have to admit that I never tested this myself.