We've been hit by this at work as well. We had to add CAPTCHA and a several other techniques to defend against this. How it works: 1. Attacker leases 1 or more premium rate numbers in an international country. - Attacker can lease a premium rate number for as little as $10/month - Typically, the attacker gets to keep 70% of the money generated by the premium rate number. 2. Attacker then finds companies with OTP (One…
> premium rate number costs 10 cents wut, the absolutely most ordinary (in the realm of single telecom) text costs me ~6.5 cents
I'm in the US and any of the big carriers offer unlimited texting as a baseline, and we have pretty crappy carriers compared to a lot of the world.