Are there any virus today that can completely destroy a computer?
This is the biggest threat, but if out there there's a virus that can fuck with your HDD/SSD firmware then you should be worried about that. That is the ultimate bricker.
Pretty much anything that runs at ring 0 could in theory rewrite firmware with bad shit. However if you happen to have a motherboard with a switchable BIOS, you could save your ass pretty quickly.
If we're talking about halting and catching fire, then not really. I'm guessing you *COULD* write code that tells the BIOS to overvolt to 2.0V and fry the CPU, though.
Magistr and Kriz are two relatively modern viruses that attempt to destroy hardware. They should work fine on 32 bit Windows systems. I've never tested them on 64 bit though.
No one really makes hardware destroying viruses any more though. Now it's all about botnets and ransomware.
>destroy a computer?
That's some Heath Ledger Joker-tier kind of virus. Nobody makes those anymore.
The reason is that, if they already get as far as being able to execute that type of code on your machine, they will rather use that opportunity to somehow get money out of it by encrypting your files for ransom or running coinminers. Fucking greedy jews, I swear.
There aren't that many and the reason is simple: no cracker would go for sheer malice when he can go for malice and cash, all while the latter is a lot easier to implement.
Which is why today almost all decent malware is either ransomware or botnets.
The 1337 h4x0rs sell 0-days exploits, rootkits and so forth to the highest bidder, among which you can count governments, espionage organizations & wealthy criminals.
If you're good at it and don't have a conscience, there's a lot of money to be made - but not from simply fucking up someone's firmware because you can.
How often are you writing assembly with ring 0 permissions? Maybe you could brick a shit ton of embedded hardware (I know I've fucked up TI calculators by accidentally putting the display in test mode), but I doubt you could do that to a desktop without trying to.
Couldn't a virus write data and interrupt the process generating bad sectors on the disk? Given enough time it could corrupt the entire drive or break a critical file and crash the system. Seems simple to do but I would think it's been done before and there are safeguard in place.