A vulnerability in the way that computers running the software handle fonts could be exploited by to seize control of a computer, Microsoft said. The company has already issued a fix for the problem, which it recommends that users download and install as soon as they can.

Users can patch up their computer by running Windows Update, which can be accessed through the Start button. Many users choose to have updates install automatically, in which case it should already have arrived on connected computers.

An attacker using the vulnerability could "install programs; view, change, or delete data; or create new accounts with full user rights”, Microsoft said.

Microsoft said that the vulnerability was already public when it issued the update, but that it "did not have any information to indicate this vulnerability had been used to attack customers”. "Our analysis has shown that exploit code could be created in such a way that an attacker could consistently exploit this vulnerability,” the company said.

The vulnerability affects all version of Windows, including Windows Vista, Windows 7, Windows 8 and 8.1, and business and server versions of the operating system.

Hackers would be able to take over computers just by tricking someone into opening a specific document, or sending people to a certain webpage. The vulnerability was a result of the way that the Windows Adobe Type Manager Library — which looks after the various fonts stored on the computer — dealt with specific kinds of fonts.

(independent.co.uk)