Help me disable a PC...

[shadowhawk2020]

I am at the point in my PC repair class that we are taking other student's PCs and making it hard for them to fix them.

I can do hardware replacements with bad items but no actual damage. Since the other students are in the room, I may do hardware as a decoy and do software damage.

We have basic Dell computers with Windows XP with service pack 2. We have free reign to install viruses or any other malicious software we want. We can delete files and anything else we want.



Last week I used a bartpe disk and a plugin to give a guest account admin privileges, and the admin account have guest privileges. I am looking for sneaky tricks to pull...

[zekeburger1979]

I read an article a few weeks ago about a TV station that took a PC, unplugged the hard drive and then took it around to various local and national repair shops to see if they could fix it. Quite a few recommended expensive fixes. A couple figured it out right away and didn't charge anything.

[Nifty03]

Originally Posted by shadowhawk2020

We have free reign to install viruses or any other malicious software we want.

Install Vista on it, they will never fix it.

Would putting the Reset Bios jumper on Reset do anything strange, that might be hard to find.

[Mopower]

Originally Posted by Nifty03

Install Vista on it, they will never fix it.

Because it won't need to be fixed?

[Nifty03]

Originally Posted by Mopower

Because it won't need to be fixed?

I's just kidding. I have Vista and have had no problems with it, so yes, because it wouldn't need to be fixed. (I said " " !)

If you can find a flaky power supply that works only some of the time could be a hard problem to find also. (at least for me!)

[Groucho]

If you can get a hold of a bad memory stick, that is a beauty because if the memory is mostly working the problems will manifest in different ways including, but not limited to, writing bad data to the hard drive.

[Nifty03]

Originally Posted by Groucho

If you can get a hold of a bad memory stick, that is a beauty because if the memory is mostly working the problems will manifest in different ways including, but not limited to, writing bad data to the hard drive.

Good one, or pull the HD connector out part way on one side (PATA only I would guess) so it still sees it but corrupts the data sent.

[4KRG]

Disable the CPU fan so it overheats, that one is always fun to watch

[wmansir]

Originally Posted by 4KRG

Disable the CPU fan so it overheats, that one is always fun to watch

But that would be too easy to catch. Now, replacing the CPU heatsink's thermal paste/pad with some sort of insulator....

One tricky thing you could do would be to put in a scheduled task to re-break the system, but don't be stupid like most virus writers and call it "Haxor PUTER!!!", give the task a name and description that make it look legit. I think this is more difficult on XP systems though because the Vista/Win7 task scheduler has a lot more legit MS junk. I've seen malware do this, but they were stupid and filled the Task Scheduler with about 30 of the same, obviously malware, task.

But then it sounds like you guys will have free reign to just do a complete system restore, which would eliminate anything on the software side short of a hacked bios or boot sector virus. A boot sector virus would probably be picked up by most virus scanners, so there's not much point to it. I've read of firmware rootkits, but have no experience with them. They sound like a bitch to deal with.

[shadowhawk2020]

Originally Posted by wmansir

But that would be too easy to catch. Now, replacing the CPU heatsink's thermal paste/pad with some sort of insulator....

One tricky thing you could do would be to put in a scheduled task to re-break the system, but don't be stupid like most virus writers and call it "Haxor PUTER!!!", give the task a name and description that make it look legit. I think this is more difficult on XP systems though because the Vista/Win7 task scheduler has a lot more legit MS junk. I've seen malware do this, but they were stupid and filled the Task Scheduler with about 30 of the same, obviously malware, task.

But then it sounds like you guys will have free reign to just do a complete system restore, which would eliminate anything on the software side short of a hacked bios or boot sector virus. A boot sector virus would probably be picked up by most virus scanners, so there's not much point to it. I've read of firmware rootkits, but have no experience with them. They sound like a bitch to deal with.

Yeah, software is kinda boring, because most of the people in class restore, or reinstall windows when they get frustrated. Sometimes that is the only option, but in the real world people do want to lose all their stuff. So starting from scratch is not a vailid option.

It would be much more fun to have some set paramaters.

[zuffy]

- switch power supply to 220v
- use crossover cable instead

[4KRG]

Originally Posted by wmansir

But that would be too easy to catch. Now, replacing the CPU heatsink's thermal paste/pad with some sort of insulator....

They are using Dells which have a heat sync cover (green plastic usually) so it might not be as easy as you think.

You also want it to be a real world problem right? You don't want to fabricate something like an insulator in place instead of thermal paste, that isn't a real problem.

You could also knock out the video card fan, that is good for some strange artifacts on the screen when it heats up.

You can also 'low volt' the fans so they still spin, take a 12V processor fan and hook it up to a 5V lead.

[dvdsteve2000]

Originally Posted by shadowhawk2020

I am at the point in my PC repair class that we are taking other student's PCs and making it hard for them to fix them.

Just say "Here bitches, fix this!!"

[wmansir]

Originally Posted by 4KRG

You also want it to be a real world problem right? You don't want to fabricate something like an insulator in place instead of thermal paste, that isn't a real problem.

You can never underestimate how inept the last person to work on a computer was. Ok, maybe inserting an insulator is a bit much. Not having any thermal paste at all could be a real world problem, although I'm not sure how effective it would be at busting the computer.

The problem with hardware failure is it's hard to replicate those really difficult edge cases where something is just failing without being obvious. For example I had a PSU that would produce occasional voltage dips. Even at it's worst it only caused system errors maybe a couple of times a week running 24/7. I wouldn't even know how to go about replicating that, at least not without risking electrocution of me or the rest of the hardware.

[DarkestPhoenix]

Originally Posted by zuffy

- switch power supply to 220v
- use crossover cable instead

I saw a d-bag at my office plug in his 110v comp into a 220v outlet....funniest shit ever.

You could try doing that then handing them the charred remains.

Office smelled like dead computer for half a day.

[Mopower]

Take the CMOS battery out.

Disable USB Keyboard support in BIOS

Pull the power cord from the motherboard

[Mopower]

Originally Posted by Nifty03

I's just kidding. I have Vista and have had no problems with it, so yes, because it wouldn't need to be fixed. (I said " " !)

If you can find a flaky power supply that works only some of the time could be a hard problem to find also. (at least for me!)

Sorry I misunderstood what you wrote.

[Drexl]

Well, he said he can't damage anything.

I like the bad RAM suggestion. I had a stick that went bad, and the power supply would start up and shut off before the computer could boot. A mixture of RAM that's completely bad and partially bad would be better.

I'm sure there are many things you can mess with in the BIOS, so I'd leave the battery in. Then again, I imagine they could think of just clearing the CMOS.

[ernestrp]

One of my sisters was trying to install or run something and it said she needed more memory......She deeted her C: drive. It was back in W98 days.

You could play with the ram timings or something else in the bios. I would imagine people have done that and had to take it somewhere for someone else to fix.

[Ranger]

Startup password from the BIOS.

I think you should be able to disable explorer.exe at startup and only way to get it back is ctrl+alt+del and start new process and type explorer.exe.

[fumanstan]

Underclocking the system would be fun, just to make it run really slow. Memory timings is a good idea.

You could mess with group policy and disable a bunch of things.

[shadowhawk2020]

I am laughing my ass off at a bunch of these suggestions. I love the idea of underclocking the computer...

disabling explorer, disabling usb keyboard would be a nice touch also.

[Drexl]

There should be some jumpers to change, like on the hard drive. If it's PATA, you can screw up the master/slave assignment, and sometimes a drive will have a jumper to limit the size to 32GB (if it's larger than that). I don't know what happens if you set that jumper when it's already formatted though.

[4KRG]

Originally Posted by shadowhawk2020

I love the idea of underclocking the computer...

since it is a dell, you probably can't

[fumanstan]

Originally Posted by 4KRG

since it is a dell, you probably can't

Oh yeah, that's true. Same with memory timings