It's good that he went public about it, as this is the sort of thing that can cause international tensions when the target assumes it's a state-sponsored attack. So many cyberattacks by individuals or small crime outfits get misinterpreted as state-sponsored because they're "sophisticated".

Things are really easy to misinterpret, like when Ukraine's undercover attempt to capture Russian PMC soldiers resulted in Belarus thinking Russia was attempting a coup in Belarus.