The target of the largest ransomware attack in history has obtained the key to unlock impacted systems.

Kaseya makes IT management software used by companies around the world. As a result, it’s a tempting target for hackers, since compromising its software can potentially compromise thousands of its clients and their clients. This most recent attack compromised as many as 1,500 customers around the world.

REvil, the gang believed to be behind the ransomware, went dark in the aftermath of the attack. According to The Washington Post, Kaseya has now received the unlock key from a “trusted third party.” The company has verified the universal decryptor key works, and is rolling it out to customers.

The news is a welcome relief to the victims of the attack, and should speed up their recovery.