A glitch in Google’s security update on Saturday morning caused links to every search result—including Google’s own pages—to get flagged with the warning: “This site may harm your computer.” The errors caused panic among users around the world who at first feared the popular search engine had suffered a major security failure. The problem which lasted for approximately 40 minutes has now been acknowledged and fixed by Google. The reason for the hiccup, as explained by Google, was due to a human error in the list of URLs Google uses to identify and flag websites known to install malicious software.

Here is Google’s explanation posted this morning on its official blog:

“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.”

Update from Google: The post has been revised and StopBadware’s explanation added. Feb.2.2009

Updates:  UPDATED Feb 03, 2009 2:35 PM PST
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What is StopBadware.org, anyway? StopBadware Blog, Feb.3.2009