Never click on any unknown link. These links are promoted by hackers in different ways. They send most phishing links via email. Don't join any giveaway that wants your private key. I saw that by attending the giveaway, many were victims of hackers. Simple.
It is true,
Most crypto users become a victim of hacking because of this trick. And since this is free they just click the link and log in their wallet on the fake website that hackers made. That's why it is better to investigate if the website is legit first and see for yourself if it is really a giveaway. Also, don't just easily log in the wallet to being a victim of hacking.
I would suggest every time you access a website check it's SSL certificates and you should be able to easily catch scams and hacks. Moreover you must always check the sender's email address and carefully match it. A few point to always keep in mind.
1- Any offer sent to email that sounds too good to be true is a scam more often than not.
2- An email that urges you to change password is usually a phishing attempt.
3- Getting an email that asks you to claim any sort of prize is usually a scam.