Received the following message: "Hello, I have this number in my phone book but no name. I wonder if we are friends?"
My contacts have my number. If they deleted me ages ago, I probably no longer need to hear from them. And no name came up on my end anyway.
But I suspect this is a phishing scam, especially after seeing some complaints on this number here.
Never call them back. If it's legit, they will leave a message or try again. Never text back. That is what they want. Tidbits of information to collect or just to know the number is still active to onsell.
Your number can be harvested from many sources. Be careful folks.

Probably a scam, I’d like to know how they get my mobile number

No voicemail

Guessing this is a scam number, it’s outta control out here

No message left, unknown number, likely scammer

I've got no idea who this was. Probably another spam call??