Google’s Warning Message Sent by Mistake

Google said that for nearly an hour on Saturday, users got an erroneous message when they did searches on many sites, saying, “This site may harm your computer.”

The problem began at 9:30 a.m. ET and ended at 10:25 a.m. ET

“What happened? Very simply, human error,” the company said on its blog. Google said it flags search results with the message when a site is known to install malicious software. Instead, many other sites were affected.

A detailed explanation of the problem was posted at one of Google’s blog sites.

The blog post said in part:

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 maintain a list of such sites through both manual and automated methods. We work with a non-profit called StopBadware.org to come up with criteria for maintaining this list, and to provide simple processes for webmasters to remove their site from the list.

We periodically update that list and released one such update to 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.