WASHINGTON – Internet users scanning their Twitter feeds or Facebook accounts Sunday might want to add one more quick click to check their computer for malware.

Thousands of people around the country whose computers were infected with malicious software more than a year ago faced the possibility of not being able to get online after 11:01 a.m.

At 11 p.m., the FBI planned to shut down the Internet servers set up as a temporary safety net to keep infected computers online for the past eight months. The court order the agency obtained to keep the servers running expired, and it was not renewed.