Could a malicious air drop make a transaction sending all your BTC to them, and then you sign it, and then they broadcast it to the network?
Or is signing a message different than signing a transaction?
Are Airdrop safe.? well my ans is no. Because good projects are not going to give you free money. But yes there is some projects that told you to do some task for them like subscribe there social channels or register there website, for those matter you can inquire those project and then you can fill the application. Please avoid those airdrop which told to you such a lot of money. just think why anyone give you money without any reason. Do not give them any personal information for your safety. keep safe, think twice before you do something.