Been noticing a LOT of ads on Facebook for free USB thumb drives and USB thumb drives to "speed up your old computer". Now you can get reputable software that boots from a USB stick that will clean the PC of bad viruses. In fact they are often less money to get than to take it to the shop and have them clean it with exactly the same thing. As well often a shop will just wipe the HD and reinstall windows. This is of course not a great thing for your data...
So you get this "free" USB stick or this $8 (shipped) cleaning stick and plug it in. Well being that a USB device can have auto-run programs on it to install the drivers for it, this is not a good thing. See a virus like that will be smart enough to pretend it's a driver then poof you are infected and your bank account is empty. If you are lucky your anti-virus will catch it and not allow it to install. But the cleaning stick is another story as the instructions are to boot from the USB. This in the normal case is to get around the virus shutting down the cleaner as it will not have the chance to run. But in the case of some random thing off the net like this, you have a very real risk of installing ransom ware that will run some time down the road or a keylogger that will copy and transmit your passwords and login date to some hacker some place.
Now a lot of people are smart enough to NOT pick them up off the street and stick it in the PC. A lot of businesses will even have the USB disabled on their terminals and laptops to prevent this from happening. But you don't have it disabled. A good anti-virus will scan a device when it's plugged in to see if it's a risk. But a lot of people will not have this feature turned on as it's "annoying". Sigh.
It's the same risk as all these "free game" sites on the net. Flash is NOT our friend unless we know the site is not a risk. These game sites pop up all over the place and often when they get black listed they will just change servers and URL's. It is easy for flash to infect you as you literally tell the PC it's OK to run the app. This gets around the ant-virus some of the time and poof you are infected.
What I really love is all the Mac users that literally think there is no way for them to be infected. If I had $10 for every time I heard or read a Mac user saying "there are no virus for the Mac" I could have my own house by now. Fact is there are a lot of them out there and the fact that most Mac users do not run anti-virus means that a lot of them end up infected with at least spy ware or adware. I remember telling my one friend just what to install and run and after he did, he told me he had over 800 infections of spyware and 1 kind of bad virus on his Mac.
It's really a good idea to have not only an anti-virus but as well an anti-exploit browser ad-on. Adblock plus is a must BTW. It kills the bad ads. There is talk that it will replace the bad ads with it's own ads sooner or later - even if it does this, it's a lot safer than the ad services like click spring who literally let anyone advertise and do NOT have any protection or standards like Google ads do. BTW most infections come from click traps who use ad services that do not filter out the bad ones.
So be smart and play it safe, have a good anti-virus with a link scanner and some kind of anti-exploit installed. And what ever you do, do NOT fall for "free" or "speed up your computer". Almost always these speed up apps are not safe. While I'm at it, never use a registry cleaner you got for free - they will mess you up a good one. Hell I don't recommend you use the one that comes with CCleaner. Anyway, safe computing and use your head. Oh and all these "get it free sites" are a hell of a risk. Just don't do it.