Antivirus Used by Millions Blocked All Google Sites by Mistake, Sowing Chaos

A popular antivirus that’s used by millions of people around the world blocked all Google sites and services on Wednesday due to a mistake. 

For around an hour on Wednesday morning, some people who had Malwarebytes antivirus installed on their computers could not visit any Google site or use services like Gmail or the Google Play Store, according to people who complained about the issue on Twitter.

Naomi Clark, a game designer and teacher at the New York University’s Game Center, who wrote on Twitter about the issue, told Motherboard that websites “wouldn't load, as if blocked by a firewall.”

“But even before that, my Malwarebytes installation started showing me system notifications that a malware site had been blocked, dozens per minute, all Google domains,” she said. “That's how I realized what must have happened.”

Clark said in a tweet that this issue “reminds you how Google ad-tracking IPs are peppered over absolutely everything.”

Kyle Polley, who works in cybersecurity, said that his fiancé was affected by the issue. 

“She got what felt like an endless number of alerts that are along the lines of ‘malwarebytes blocked <browser name> from <google website>’ where <browser name> is either Chrome or Edge and <google website> was google.com, ads.google.com, play.google.com etc. Any Google site or any site that used Google in some way failed to work,” he told Motherboard. “She had to turn off Malwarebytes in order to get work done.”

Marcin Kleczynski, the CEO and co-founder of Malwarebytes, told Motherboard that it was “an accidental false positive. Fixed fairly quickly,” and that it affected only Windows users.

“Unfortunately always a noisy event when you have millions of users,” Kleczynski added. 

Malwarbytes first acknowledged the issue around 11:30 a.m. ET in a tweet. 

“We are aware of a temporary issue with the web filtering component of our product that may be blocking certain domains, including http://google.com. We are actively working on a fix and will update Twitter as soon as we have more information,” the company wrote on Twitter. 

About an hour later, the company wrote that the issue was resolved, and that the update “should happen automatically.”

Kleczynski said the issue lasted around 30 minutes. Clark said it persisted for around an hour and a half for her. Several people responded to the company’s tweets saying the issue was fixed complaining that it was still ongoing. 

Google did not immediately respond to a request for comment. 

UPDATE, 4:17 p.m. ET: This story was updated to include additional information.

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