Could my usb flash drive be harmful to someone else's pc?

Yes, this can happen. Its never happened to me personally, to my knowledge, but a virus can hide itself in a file in any number of ways, and can be programmed to be invisible until a certain date, or until certain actions are performed. Your friend’s concern is valid. If there were a virus, worm, or any other malware, it would hide inside a Word file, an email file, a picture file, a video file, or an audio file. I’m sure there’s other ways too.

However, if your USB drive is empty, (be sure the option to show hidden files is checked so you really know whether its empty or not), then your friend really should not be concerned. An empty USB (empty of hidden files and all files) is harmless, far as I know.

Yes it is possible your usb drive could be infected. It’s a bit paranoid, but it’s a remote possibility.

I’ve had my laptop tell me that my thumb drive had a virus on it several times…

First to do is formate the flash drive before each use.For savety reasons.Avoid Troyan

@Kraigmo how do I opt to have these “hidden” files emptied?
@pathfinder how do I format and what is “Troyan”?

Man! “I don’t know much tech-nol-ogy” (I just sang that).

By the way, thank you ALL very much for the prompt help and response!

@valdasta your second question causes me to reassess my assumption that an empty USB is safe. Some hidden files are supposed to be there, and part of the USB drive. I can now think of how theoretically, a virus could attach itself deep within those hidden files, in a place that would be hard to notice. So now I think there is no 100% safe USB drive. Virus-scanning the USB drive and keeping it empty of added files should give you okay odds in being safe, though.

@valdasta: Ignore pathfinder. He never says anything that makes sense. You can read his other answers by going to his profile. They’re all the same.

I do think though that flash drives can carry a virus. And reformatting would probably eliminate the problem.

But I am an Apple person so I don’t have to worry about such stuff, so I am not completely sure!!

Every data medium could carry a virus. As far as I know an usb stick is harmful because of the autorun features. A virus could copy itself to anywhere on the stick (usually the hidden recycle bin) and modify the autorun file on the stick to launch itself onces you hook up the stick to another computer. There are probably more ways for a virus to nest on your stick that I myself am unaware of, but to counter the autorun problem I use panda’s autorun vaccine (free small program that modifies all the possible autorun files on your stick so that they cannot be altered anymore). I feel a little more safe now, but always watch out with sticks, especially those of other people.

Conficker is an example of a worm that can spread through detachable drives. To defend yourself against malware that spreads this way, you need to disable autoplay for all detachable storage. If you have Windows XP, you can download the Tweakui tool , which has a convenient applet for disabling autoplay on multiple drives.

@rooeytoo , formatting a drive isn’t a guarantee that malware will be removed. And the only reason Apple users don’t get hit with this stuff is that you’re too small of a population for the perpetrators of these things to bother with.

O and I forgot, always right-click and choose open instead of double-clicking on the drive. Don’t know about Vista and 7 but in XP double-clicking a drive triggers the autorun.

Use the same safety rules with your thumb drive as you do sex.

Don’t let just anyone plug their thumbdrive into your computer, you never know WHERE its been.

Many companies disable the use of USB ports because the spread of viruses and other nasties via thumb drives is such a problem. I can’t tell you how many hours I’ve wasted cleaning pcs on workstations in India because the employees love to buy ‘cheap’ thumbdrives from China on eBay that come pre-infected and plug them into their workstations.

There is a file you can copy to your thumbdrive to disable the autorun and that can protect you to a degree. Not sure where you can get it, my boss gave it to me.

@markyy I downloaded panda….thank you. Once it gives my usb drive the “vaccine”, does it have to do it every time I plug it into my pc or anyone else’s; is auto run disabled from now on, on that drive?

@Daethian how does the public library keep their pc’s clean? Lots of tech hours?

@valdasta Nope, only one time. The idea is that it creates autorun files in the same places a virus does, but make them disabled (you know, so they can’t be overwritten/changed). Autorun will not be disabled (that’s something windows does, not the drive), but just an empty file so no harm will be done. In other words, even if there was a virus on there, it will never be opened automatically (unless you do it manually by doublicking on the executable, .exe).

@valdasta , when you use a public computer, you will be using a restricted account that in theory does not have administrative rights to pass on to a bugaboo. I say “in theory” because these things still find a way to get in. When I was taking classes at the local CC, the administrators would simply wipe and re-image the student machines daily.

yes

if the drive has autorun enabled

or if there is executable content