This week a hacker who stole a significant amount of money from a company appeared to right the wrong with an unexpected move.

CNN reports that an anonymous hacker who stole more than $600 million from the decentralized finance platform Poly Network returned nearly every cent.

The seeming display of a conscience didn't end with this.

When the company offered the hacker a half-million-dollar reward for alerting them to their security vulnerabilities, the mysterious cyber whiz turned the money down.

The hacker's unusual behavior brought an end to what some refer to as one of the biggest cryptocurrency heists in industry history.

Poly Network tweeted Thursday that the hacker — whom it is calling "Mr. White Hat," a term that refers to an ethical hacker who raises awareness of security flaws — returned all of the stolen funds, except for a small percentage that had been frozen by the cryptocurrency issuer Tether following the hack.

The money was deposited to an account that requires both the company and the hacker to manage jointly.

"To ensure the safe recovery of user assets, we hope to maintain communication with Mr. White Hat and convey accurate information to the public," Poly Network said.

In messages accompanying the returned funds the hacker claimed it was "always the plan" to give the money back.

"I am _not_ interested in money!" the hacker said, and added: "I would say figuring out the blind spot in the architecture of Poly Network would be one of the best moments in my life."

Experts have pointed out that it would have been no easy task for the hacker to spend the stolen funds. CNN notes that as blockchain transactions are publicly recorded, it would have been difficult to launder money anonymously.

Whether the hacker acted out of good motive or self-preservation is up for speculation; in any case, Poly Network is pleased to have its stolen funds returned and information that will help the company shore up its security.