Parents scammed out of 30k in crypto

As the title says my parents got scammed out of 30k in crypto but we’re not sure how exactly the guy got access to their wallets.

My dad downloaded the app Zoho on his phone but his Coinbase wallet was on his computer and somehow the guy gained access to all of his wallets on his computer without ever downloading zoho onto his actual computer. How is this possible? My dad never gave them his usernames or passwords or seeds or anything and somehow the guy got into their account. Has anybody had experience with this?