my friends lost his coins from offline wallet when he was chatting online on facebook messenger
sure he can't restore his coin
so how can protect offline wallet ?
Something is definitely missing in your write up, did your friend disclosed his private key to the person he is chatting with? Or did he write it in an open place that someone else can easily get access to, To protect your offline wallet, make sure that u back up your private key in different places, and avoid exposing it to anyone