On January 31 between 6:30 a.m PST and 7:25 a.m. PST Google's search engine began flagging every search result as malware with the message, "This site may harm your computer." The error was reported to be global.
Google quickly fixed the problem within 55 minutes of the problems arrival. They have also responded via the Google blog stating the problem occurred due to human error after a '/' was added to the list of websites that StopBadware.org considers to be malware infected. Since / is in every website this means that the entire internet was flagged as malware.
Here is the official response from Mayer on Google's Blog
"If you did a Google search between 6:30 a.m. PST and 7:25 a.m. PST this morning, you likely saw that the message “This site may harm your computer” accompanied each and every search result. This was clearly an error, and we are very sorry for the inconvenience caused to our users.
What happened? Very simply, human error. Google flags search results with the message “This site may harm your computer” if the site is known to install malicious software in the background or otherwise surreptitiously. We do this to protect our users against visiting sites that could harm their computers. We work with a non-profit called StopBadware.org to get our list of URLs. StopBadware carefully researches each consumer complaint to decide fairly whether that URL belongs on the list. Since each case needs to be individually researched, this list is maintained by humans, not algorithms.
We periodically receive updates to that list and received one such update to release on the site this morning. Unfortunately (and here’s the human error), the URL of ‘/’ was mistakenly checked in as a value to the file and ‘/’ expands to all URLs. Fortunately, our on-call site reliability team found the problem quickly and reverted the file. Since we push these updates in a staggered and rolling fashion, the errors began appearing between 6:27 a.m. and 6:40 a.m. and began disappearing between 7:10 and 7:25 a.m., so the duration of the problem for any particular user was approximately 40 minutes.
Thanks to our team for their quick work in finding this. And again, our apologies to any of you who were inconvenienced this morning, and to site owners whose pages were incorrectly labeled. We will carefully investigate this incident and put more robust file checks in place to prevent it from happening again.
Thanks for your understanding.
Posted by Marissa Mayer, VP, Search Products & User Experience"