You'll occasionally get a random WhatsApp message from an unrecognized number that turns out to be a buddy who's changed numbers, but most of the time, they will be spam.
Frequently-Forwarded Message
It's highly unlikely you'll ever have such a sender in your address book, which means that when it lands in your WhatsApp inbox, it will always show as an unrecognized number.
Click on the link at your peril; it's going to try and illicit your personal details, banking details, login credentials, or any other form of data that has value on the dark web.
If you receive such a message on WhatsApp, and you've not tried to log in anywhere recently, don't worry. It doesn't mean someone is trying to hack your account. The message is spam, and you can block it.