The Homeland Security’s cybersecurity advisory division is cautioning Windows 10 users of the possibility of a wave of cyberattacks due to the recent publication of an exploit code.

“Malicious cyber actors are targeting unpatched systems with the new [threat],” the agency noted on the Homeland Security web site. The agency said it “strongly recommends using a firewall to block server message block ports from the internet and to apply patches to critical- and high-severity vulnerabilities as soon as possible.”

The agency also referred concerned parties to Microsoft’s security guidance posts and notes published by the U.S. Computer Emergency Readiness Team at us-cert.gov.