Hey! So me and a few other people at work were having this discussion - the kind where none of us knew what we were talking about, but all of us pretended we did. But the issue never got settled.

Would it be possible or even likely that a virus would attack and destroy all of a certain type of file (ie .doc, .jpg, .xls)?

I believe they can in addition to replicating and spreading corruption... I think anyway

It is possible.

It is likely, if the virus was designed to destroy the files, or if the virus was designed to spread itself through a certain type of file (i.e. .doc, .jpg, .xls) but the virus author was untalented and Russian.

.doc, .xls are fairly likely because you can embed executable code in them. .jpg isn't likely, unless it is targeting an exploit in some graphics package.

Why?

It started as a joke someone made about sending a virus to destroy all of the competition's spreadsheets. (Promise we were kidding) Then someone didn't understand the concept of jokes and started going off about how impossible that would be outside of movies and, someone else said we're all terrible people for even joking about that. Then someone else made a comment about porn on the humorless guy's work computer and sending said fictional virus to destroy it all, meanwhile the guy in question was insisting that it wasn't possible outside the movies and the other was maintaining that we're still terrible people. It spiraled from there.

Um... impossible outside of movies?

If you can get a virus onto a computer, it can do anything that any other program can. Basically what I'm saying is that if a user can edit a spreadsheet, any program that user runs will be able to edit it, too.

The hard part is getting the program to run. But considering how retarded the people you're talking to seem to be, you could easily do it with social engineering - send them BIRTHDAY_GREETINGS.EXE and tell them it's an "e-card."

Here's a better idea: a virus that 'adjusts' dollar values in excel spreadsheets, then sends an e-mail to the SEC using a random address from the person's outlook address book. It'd be a good idea to use some kind of heuristic to guess if a spreadsheet contains important financial records. Probably wouldn't even be hard, it'd just be a lot of statistics work to get the heuristic right.

Totally possible.

Or a virus that uses machine vision algorithms to detect video files containing nudity, and replace them with horse porn. This one is pretty hard, probably make a good msc thesis - porn detection algorithms are cutting-edge, although very real.

I'll take all my e-cards in pictorial PDF form, please and thank-you-kindly.

EXE e-cards... *shudder* I've personally seen that happen to one of the moderately more gullible kids in my class. Ugly stuff.

aha, yeah, because PDF is safer than an arbitrary EXE file.

People send e-cards in PDF form?

Why

Bahaha can you imagine the chaos? Not just losing bids and price fluctuations, we're talking lawsuits.

I've heard something about people starting to develop a program that can detect nudity in videos, haven't I? Or am I just making that up?

Yeah, Google (Youtube) and Chatroulette do work on that kind of thing IIRC. It's a pretty cool area for research in comp. sci.

I doubt they actually use them on their live sites though.

Fixed.

I've also heard that the Xbox kinect/vision cam can do this in a video chat.. But I haven't tried taking my pants off yet to see if it works.

It is definitely possible. Almost ten years ago, several of my friends got hit by an e-mail virus that corrupted every single .jpg image on their computers. It was not like the files were infected with the virus itself, but they became useless. It was simply one of those viruses that was designed to be destructive. I'm trying to remember the name... The popular name had the word 'happy' in it because of the e-mail message it came with.

It was especially bad for my two friends who had just been on a 6 month trip through Australia, NZ, Indonesia and South-East Asia. They lost all their pictures, except for about 20 of them that they had printed on regular printer paper. It was the first time they brought a digital camera on vacation, also. They had backups on their second hard-drive, but of course these also got destroyed.

You beat me to it. I don't see the point either.

I never got an e-card, so I wouldn't know the MAGIC of getting one.

The 'magic' is in wondering why your friends hate you so much if you did get one. Seriously... How socially ackward do you have to be to send an e-card?

You're all getting ecards the next time you post a birthday thread.

Maybe Steven this year for christmas will send out ecards instead of christmas cards.

It is. I can mouse-over preview PDF files without actually opening them, so I can view a PDF without needing to download it. If it's really an e-card, I can read it without having to open it. If it's a virus... then I just never open it anyway.

All the minor thought of a greetings card with even less effort!

probably about this socially ackward...>>> The It Crowd

If you're previewing it, your computer has opened it. Virus has already gained access, done. You can't "preview" something without opening it.

If you're talking about GMail's HTML preview system, that would work not because PDFs are safe, but because GMail is essentially stripping the PDF down to bare text. The same as it does for docs, xls, etc. Not to mention that virus PDFs CAN look legitimate, even in GMail's preview.

In short, any perceived safety in PDFs has nothing to do with the fact that it's a PDF and everything to do with how GMail handles attached files that it can read.

Finally, IF you don't use GMail, well, haha. Hate to break it to you, but you did download it and you did view it, it was just in a "preview window".

I do use Gmail, and I don't open the file, even if the preview looks safe.
I just really hate e-cards. :-/ Even the 'safe' ones are usually confetti-drenched abominations to the optic nerve.