Recently, there have been Private Messages going around from random people that includes something like:
Never click on unknown links if you're unsure of it. Most of the time unknown links can cause viruses which in this case, did. If you have please make you change your password AND scan your computer for viruses using tools such as:
How to tell what "bit" to download: http://support.microsoft.com/kb/827218
Well if you don't want to go through the trouble of reading/doing all that, you can just download both and one of them should give you an error saying that "This is for xx bit type only"
These are probably the best tools that I have used for scanning my computer for viruses. Please make sure that once you remove the viruses from your computer to be sure to change your passwords as well.
Don't EVER type in your Username and Password on sites that you are not familiar with. EVEN if it does look like something you visit often. People can steal code and make pages look identical so MAKE sure the www._________.com is something you are familiar with.
Also please leave the person's username that PMed you so that we can take the appropriate actions