The Redmond Giant was planning to wait until April 10,
but will now issue the patch tomorrow.
According CNet, testing had been completed earlier than anticipated and so the company decided to release the update ahead of schedule to help protect customers.
Microsoft believes that the attacks and customer impact will be limited, but the company said that it encourages customers to download the patch when it is made available.
Microsoft said it is also working with law enforcement to track down the attackers.