WATCH out, Facebook users: Hackers are finding flaws in the computer-programming language JavaScript and planting malicious code in profiles on social-networking sites. Once hackers break into a profile, they can steal data and turn victims’ PCs into remote-controlled machines that spread malware. A typical case goes like this: Messages posted on your Facebook page urge you to view a video that claims to be hosted on a normal website -- say, the Google website. But when the link is clicked, you are diverted to a website containing malware. Then the malicious code enters your e-mail box and spreads the same message to your Facebook friends. The same message will be sent from the e-mail boxes of those friends to their friends, and so on. The lesson? Be sure you have proper virus protection, and don’t open anything until the source is confirmed.