Ask HN: How can scam callers fake a mobile phone number?
by fxtentacle on Hacker News.
I’m with T-Mobile and I just received a phone call on my mobile phone from another number where everything except for the last 3 digits was exactly matching my own number. I found that suspicious, but I was curious enough to pick up the call. The other person greeted me with “We are very important this is Interpol!” in seriously broken English, so I suspected a spam call and hung up to try to call them back. That didn’t work because the phone number they were calling me from does not actually exist. Like I immediately get the T-Mobile announcement informing me that this is an invalid number. Now I am wondering: – How can a spam caller call me with a source phone number that does not exist? – Shouldn’t my mobile phone network verify that the caller – which was also inside their network – is a valid subscriber? Otherwise, how can they bill someone for this call? – How does this kind of scam call work technically?