Kaseya obtains master decryptor for victims of REvil ransomware attack SHARE Information technology management software firm Kaseya Ltd. has obtained a master decryptor for victims of the REvil ransomware attack that targeted its customers earlier this month. Kaseya said in a security update today that it has obtained the tool from a third party and has teams activity helping customers affected by the ransomware to restore their environments. The company added that there are no reports of problems or issues with the decryptor and that it’s working with Emsisoft Ltd. to support customer engagement efforts. The attack by REvil started July 2 and targeted a zero-day, or until then unknown, vulnerability in the Kaseya VSA remote management application. Exactly how many Kesaya downstream customers were affected remains unclear, but estimates have put the number at between 800 and 1,500.