Microsoft tends to limit themselves to one Windows update a month – typically on a Tuesday. Yesterday, Microsoft released an emergency update to fix a serious threat caused by a bug in the way Windows handled custom fonts.
Hackers could exploit the bug by using a custom font on a webpage or document to execute a malicious code on your PC. This exploit would allow an attacker to "install programs; view, change, or delete data; or create new accounts with full user rights," said Microsoft.
Microsoft has classified the vulnerability as "critical," the most serious threat level.
A number of systems have been listed as vulnerable to the bug (basically everything with Windows). Microsoft suggests enabling automatic updates so they update that fixes this vulnerability is applied to your system as soon as possible. If you don't wish to automatically enable updates, you can do it manually through the links on Microsoft's security bulletin — you have to make sure to select the correct operating system!
The update will require a restart.
