I also believe this has happened few month(s) ago. But im not sure wether they hacked the "other" accounts or did they stole it back from the hacker him self ? That's what i remember reading.
Yes. This happened a month ago. Not sure why OP is resposting this here.
What happened is also clear in the news:
Hackers found a way to exploit a flaw in the Parity multi-signature wallet, which lead them to steal $31 millions worth of ETH. After that, a white-hat hacker team used from the same exploit to drain the remaining ETH ($85 millions worth) from other wallets with the same vulnerability, so they could prevent the bad guys from taking more ETH.