July 6, 2012 at 12:54 PM ET
Security firm Sophos has released an engagingly British video about a rather complex subject: The DNSChanger malware that is likely to knock tens of thousands of computers off of the Internet come July 9.
If you're curious about how the malware got out there, and what the FBI did to stanch the virtual bleeding, watch the first three minutes. At that point, you can follow narrator Paul Ducklin deeper into the details of checking your computer, or simply visit the FBI-authorized system-checking site, dcwg.org, to get verification. If there's any ambiguity, it will pay to go back to the video for additional help. Just do it before July 9, or you may not be able to get to YouTube (or msnbc.com) at all!