A successful ransomware attack on Kesaya, a company that remotely controls programs for businesses, has spread to at least 200 organizations. According to cybersecurity firms this is one of the single largest criminal ransomware sprees in history.
The attack, first revealed Friday afternoon, is believed to be affiliated with the prolific ransomware gang REvil and perpetuated through Kaseya.
Kaseya has issued a statement urging all its customers to immediately stop using its service. The number of infected companies is expected to rise over the weekend. Many are still awaiting a decryption key from Kaseya.
The U.S. Cybersecurity and Infrastructure Security Agency announced Friday evening that it is taking action to understand and address the attack.