An airdrop ask to send it 0ETH with 150000 GAS and some datas in DATA field. Is it safe? What could be the aim of this transaction? Thanks.
Sending 0 ETH but with data just serves the purpose of creating/storing information (that data) on the blockchain, as well as related information (e.g. sender, receiver).
The gas is just the cost of sending the transaction.
Just note that the data you send is publicly available to everyone, so it's "safe" as long as you understand that and don't send any confidential information.
Generally, no! It can be dangerous.
If you are asked to send such a transaction, you should understand what is the source code of the address you are sending to, and what function you might be invoking with the data you are sending.
Do not send arbitrary data to some arbitrary address because that is like running an arbitrary program, clicking on an arbitrary link, opening an arbitrary email attachment, and it could all be malicious.
For example, you might have a lot of some particular ERC-20 token and if you blindly send data to some address, you might be approving an attacker to be able to steal all your tokens. (The address you are sending to would be the token contract, and the data would be invoking the
approve function with the attacker's address.)
(It's possible that the data is static, but usually the data is an ABI encoding of what you will end up executing.)