The security firm confessed to the mistake in a blog post on Tuesday, and assured firms that the update has since been pulled.
"It saddens me to report that at around 3PM PST yesterday, Malwarebytes released a definitions update that disabled thousands of computers worldwide," wrote Malwarebytes Marcin Kleczynski.
"Within eight minutes, the update was pulled from our servers. Immediately thereafter, users flocked to our support helpdesk and forums to ask us for a fix."
The update definition made it so Malwarebytes protection software treated essential Windows .dll and .exe files as malware, stopping them from running and thus knocking IT systems and PCs offline.
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