Your operating system provider will be sending out a patch shortly. Install it as soon as you can.
Finally, make sure you have antivirus software installed and running (even if you’re running a mac/osx!) and follow these instructions from your vendor.
If you’re an employer, especially one of our small/medium business clients whom can’t automate this, please send this out to all of your staff and contractors, and ask them to send you an email when they’ve completed this process. Keep a spreadsheet until everyone has done this.