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Malwarebytes Delivers Buggy Update to Home, Enterprise Users

A protection update pushed out over the weekend by Malwarebytes to its home and enterprise users caused serious problems, including Web connection issues, excessive memory usage, and even system crashes.

The problematic update was released on Saturday morning, Pacific Standard Time (PST), and it was only available for 16 minutes before Malwarebytes took action to stop it from being distributed. However, it was enough for the update to reach a significant number of devices protected by the security firm’s products.

“There are detection syntax controls in place to prevent such events as the one experienced in this incident. Recently we have been improving our products so that we can show the reason for a block, i.e. the detection ‘category’ for the web protection blocks,” Malwarebytes explained. “In order to support this new feature, we added enhanced detection syntaxes to include the block category in the definitions. The unfortunate oversight was that one of the syntax controls was not implemented in the new detection syntax, which caused the malformed detection to be pushed into production.”

Some users reported that their Web connections had been blocked and the process associated with the Malwarebytes application had used up more than 10 Gb of their random access memory (RAM), causing their systems to become very slow and even crash.

The buggy protection update, namely v1.0.3798, was sent out to all versions of Malwarebytes for Windows. The affected applications include Malwarebytes for Windows Premium, including the trial version, Malwarebytes Endpoint Security (MBES), and Malwarebytes Endpoint Protection (Cloud Console). The Mac, Android, and other apps were not impacted.

Malwarebytes has provided detailed instructions for both home and enterprise users on how to recover from this incident and install the correct update on their systems. Users who had their devices turned off when the buggy update was delivered should not be affected.

“We have pushed upwards of 20,000 of these protection updates routinely. We test every single one before it goes out. We pride ourselves on the safety and accuracy of our detection engines and will work to ensure that this does not happen again,” Malwarebytes stated following the incident.

This was not the first time a security solutions provider released an update that caused headaches for home users and system administrators. Other companies involved in similar incidents in recent years include Panda Security, ESET, and Webroot.

Related: Microsoft Reissues Security Update Due to Outlook Crash

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Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.