The F.B.I. has made a public announcement stating that routers should be rebooted as a precaution against possible VPNFilter malware. This malware has already compromised at least 500,000 home and office routers as well as connected devices worldwide. U.S. CERT (part of the Department of Homeland Security) is investigating this issue under Alert TA18-145A.
Cisco’s Talos Intelligence Group has more technical details about VPNFilter malware and recommendations on how to improve router security against this threat. Cisco Talos issued a second update on June 6th 2018 with a list of known devices affected by the malware at the end of the post.