The authors behind the recent Petya ransomware attack, which rocked computers around the globe last week, have spoken out for the first time. In a message initially spotted by Motherboard on a Tor site known as DeepPaste (via The Verge), the Petya hackers have demanded 100 Bitcoins, currently worth more than $250,000, in exchange for a private key to decrypt disks affected by the attack.

Hackers behind Petya attack demand ransom of more than $250,000

Along with the message, the hackers have also made their first moves to recover ransom funds that were paid as part of the initial attack. From Motherboard:

At 10:10 PM UTC, the hackers emptied the bitcoin wallet they were using to receive ransom payments, moving more than $10,000 to a different wallet. A few minutes earlier, the hackers also sent two small payments to the bitcoin wallets of Pastebin and DeepPaste, two websites that let people post text online and are sometimes used by hackers to make announcements.

According to Forbes, the hackers also provided proof that they were indeed behind the attack by providing a signature for Petya's private key. Two security researchers confirmed to Forbes that it was real.

Following the attack last week, Microsoft noted in a post on TechNet that the Petya attack actually had far less reach than was expected. More than 70 percent of affected machines were based in Ukraine, where the attack started. That has led some to speculate that Petya was a state-sponsored attack intended to do damage to Ukrainian digital infrastructure.