Yesterday Microsoft issued a Windows security update for the Internet Explorer browser exploit that had been, well, exploited by cyberspies to get data from the computers of Google and other companies, as I previously mentioned. Criminals have already started using the same security vulnerability. The security hole can affect other Microsoft products like Outlook, Heise Security have pointed out.
If you haven't already got the update for your Internet Explorer, make sure you do. The easiest way is via Windows Update. Those who have it set to automatically download and install Windows Updates should have had it installed automatically.
If not, be sure to manually check for Windows updates and install - find Windows Updates via your Start Menu, check, download and install - or download and install the version suitable for your version of Windows and your browser from Microsoft. (For beginners - to find your browser version go to the Help > About Internet Explorer menu. If you're a non-techie your computer is very likely a 32 bit rather than 64 bit system.)