You need to be extra careful with airdrop coins, especially those with desktop wallets. They can be infected with viruses / keyloggers in an attempt to steal your wallet keys. That's not always the case but worth making a point.
I was actually very concerned about that. A friend of mine is signing up for airdrops left right and center knowing that most/many are possibly pump & dump scams. He's trying to convince me to do the same but I had those exact same apprehensions. Thanks for confirming my suspicions.