Microsoft on Monday issued an emergency fix for all supported versions of its Windows operating system, plugging a hole that essentially allowed hackers unfettered access to victims' computers.
The "critical" vulnerability, denoting Microsoft's highest level of threat, would have allowed hackers to take "complete control of the affected system," the company wrote in an
online security bulletin posted Monday. "An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights."
The flaw affects all users of Windows Vista,
Windows 7, Windows 8 and 8.1 and Windows RT, representing two out of every three of the 1.5 billion PCs running Windows around the world.
Microsoft decided not to wait until its regularly scheduled monthly security update, known as "Patch Tuesday," to issue a fix. The company last issued an emergency patch like this
in November 2014.
