They received spam messages from the group buying website "Latin America". How did they know my mobile phone number?

I used to receive some spam messages, but later my friend recommended Norton mobile phone security software to me. I haven't received any similar news since I used it. The most important thing is that it has the function of web page protection, which can protect our privacy well. Since I used it, the mobile phone runs much faster, so I shared it with the landlord.