Simple Virus For Teaching?

ed1023 writes "Currently I am teaching a 101 class on computers. It is more of a 'demystifying the black box' type of class. The current topic is computer viruses; I am looking for a virus with which I can infect the lab computers (only connected to local network, no outside network connection) that would be easy for the students to remove by hand. Can the Slashdot community point me in any directions? Is there an executable out there that would work, or do I try to write one myself, or is there one that is written that I can compile myself?"

Comments

What OS? And how annoying?

[canyon289]

What OS are you running? You could create a simple bat script that pops up an annoying message every 20 or 30 minutes to show your students an "infected' machine.

Re:What OS? And how annoying?

[crisco]

Back in the late 80s we had a bunch of 10MHz XT clones in a computer lab networked together using Novel and 10BASE2 or maybe even TokenRing. Some of the games we had ran timing loops for the original 4.77 MHz PC so we had some simple TSR that sat on the interrupt timer and ran some NOPs to slow the computers down. I thought it would be a funny prank to add this to the AUTOEXEC.BAT file on most of the boot floppies in the lab, sadly I didn't test it on more than one computer.

The interrupts and NOPs interfered greatly with the network cards, causing the whole thing to come crashing down when more than a couple of the computers were running at a time. It took at least a couple of days for the sysadmin to sort it out.

RIP George, thanks for introducing me to the Internet and I'm sorry that you didn't get to stick around for Linux and /. I should have taken your Minix class when I had the chance.

Re:What OS? And how annoying?

[xandercash]

I'm having a similar problem right now. An app I'm working on which does some low level socket networking keeps being flagged by Symantec's active scan as a virus. I'm not sure why, yet, but IT keeps telling me my computer is infected (as discovered by their nightly scans). I've explained more than once that it's an innocuous program that I wrote myself, and have assured them many times that it is NOT a virus. But they believe Symantec over me. It's VERY annoying when I compile the app and Symantec decides to delete it an hour later. Or when it's running and suddenly stops because Symantec suspended the process. It was funny the first time. (where'd the exe go? I know it was here somewhere...) but it's gotten quite tiresome. Then there's the OTHER conversation. "Why did you disable your antivirus? That's against company policy" "It keeps flagging my project as a virus" "Well, then don't write a virus...."

EICAR

[Anonymous Coward]

http://en.wikipedia.org/wiki/EICAR_test_file

Re:EICAR

[yuna49]

EICAR is detected by all AV products including ClamAV.

I'd put it in a zip file, then attach the zip to an email message. Show how real viruses propagate by mail. How about putting a copy on a USB pendrive then running eicar.com from Autostart? Any Windows AV product with a decent autoscanner should detect both of these and pop up a warning.

If you want to get really fancy you can set up a Linux box running MailScanner with ClamAV and send an "EICAR-infected" e-mail message through it. You'll see MailScanner detect the virus, put it in a quarantine, and send notices to the admin and, optionally, the sender.

For a lay audience I think it's more important to stress the vectors than to concentrate on the payload itself.

Now if you could only find a site distributing Antivirus 2010. If you do, make sure you're using a Linux machine when you visit the site. If your class understands that there's more to the world than Windows, see how long it takes them to understand why there can't really be an AV program "scanning the C: drive."

Re:Fake it.

[Missing.Matter]

The plural of virus is viruses. Just like the plural of abacus is abacuses, not abacai. Viri (or even worse, virii) annoys the hell out of me.

Write your own?

[rwa2]

It's Windows, so it's easy... just create a CD or USB drive with two files:

autorun.inf :
[autorun]
            open=installpopup.bat

installpopup.bat :
cmd.exe /k echo "Hi I am a virus"
copy installpopup.bat "C:\Documents and Settings\All Users\Start Menu\Programs\Startup"

Bonus is that it has plenty of legitimate uses for system automation for your little script kiddies as well.

Re:How about...

[X0563511]

Er, did you even read the damn post?

Here, let me help you out with the first four fucking words:

Currently I am teaching...

Re:Fake it.

[blair1q]

Well, if you want to get all prissy about the Latin, then it's incorrect to use the word to describe a single unit of the substance, in the way it's not correct to call a single water molecule "a water". Id est, since a viral program is itself a cell in the viral infection of many computers, there's no term for it other than "viral program" and no term for several of them other than "viral programs". The "virus" would be some arbitrarily bounded subset of the population of said viral programs infecting machines, which could devolve to a single program infecting a single machine, but would still not be the correct term for that program or, indeed, for the viral infection being suffered by that machine. It could correctly refer to the running program and its data (which in most computers includes its instructions) and the progress of its states, but I'm pretty sure nobody much thinks of it that clearly when using the word "virus". Nor is it correct to use "a virus" to refer to a type of virus (exempli gratia Stuxnet, Sasser, Hopper, et cetera) but only to an instance of that type of virus as it is spreading, or, again, some arbitrary subset thereof, wherein it has its physical expression and aggregate, fluid form.

As for whether it annoys you for people to use a latinate word that is both convenient and apt despite its not being precisely Latin, well, tough titty, because apparently the Latin version of it is a mispronunciation of the Proto-Indo-European word for the same gooey mess, so insisting on going only as far back as Latin for the value of correctness of form is false cognitive closure, and that gives everyone else cause to be annoyed at you.

That virus will fail on Vista/7

[Anonymous Coward]

if UAC is enabled, Explorer is not running with privileges that can write to the All Users profile.

For that matter, this will fail on any system where the profile directory isn't in "C:\Documents and Settings", which includes any non-English OS.

Use

copy installpopup.bat "%userprofile%\Start Menu\Programs\Startup" instead

Maybe ask a clamav virus signature author...

[mrflash818]

...if they know of a good virus candidate?

http://www.clamav.net/

Re:DON'T DO IT! You'll get fired

[gringer]

No where was it mentioned about creating one. Ever.... actually read the summary ffs.

I think you may have missed this part of the summary:

do I try to write one my self

Re:DON'T DO IT! You'll get fired

[L4t3r4lu5]

Yes, because he wants to make sure the "fake" virus he uses for the removal exercise doesn't contain some hidden, actually damaging, payload.

Someone has already suggested the EICAR test file, which is ideal. It pops up a message box, and is easy to remove. He can add links the various windows startup files, the registry, he can go old school and call it from a batch file, and he's safe in the knowledge that he's in no danger of hosing his systems.

Nowhere in the stub did he say he was going to teach the kids about actually writing the virus they were to remove. Reading comprehension fail.