Microsoft said on Sunday night in the US that it is planning to make available this week a patch for a Windows flaw that has already been used in an attack.
Microsoft issued an advisory on the animated cursor flaw on Thursday and by Friday malicious code was circulating that took advantage of the hole.
In an e-mail, Microsoft said it had originally planned to patch the flaw on April 10 as part of its regular monthly security update, but now it plans to release the patch on Tuesday because of the public exploit.
"Since testing has been completed earlier than anticipated, Microsoft has released the update ahead of schedule to help protect customers," a Microsoft representative said in the e-mail.
The software maker said its analysis of the data suggests that "the attacks and customer impact is limited", but the company said that it encourages customers to download the patch when it is made available.
Consumers that have Windows' automatic update feature turned on will get the patch automatically, and it is also available for manual download.
