PS: If they give you a seed in the form of recovery file, it most likely contains malware/trojan, delete them immediately!
I think deleting only won't be risk free, better he should reimage his system. If he only deletes the file, which he already opened, the malware might be rising on his hard disk. A hard disk format is the best precaution in this case.
Always confirm contract address of coin/token before you add them in your wallet & never add such fake/scam coins in your wallet, there is possibility that scammers will steal your funds when you try to sell such scam coins. There are thousands of fake currencies circulating in crypto space with similar name to legitimate coins name like Dogecoin and many others. I always check/confirm contract address on
https://coinmarketcap.com/ before I decide to buy or add coin in my wallet.
We usually connect our wallets to sites in order to get airdrops too. So, in that case, create a new wallet and then claim the airdrop. We should not connect our main wallet to random sites. This is another precaution which should be taken care of, if we want to be safe.