from Hacker News

Ask HN: What's going on with T-Mobile numbers and fraud?

by j4pe on 2/21/23, 9:37 PM with 3 comments

Is there a new variant of click/install fraud using T-Mobile?

Some of my clients, largely startups, are seeing over 50% of US users on T-Mobile numbers at a time when T-Mobile's market share is less than 25%. I haven't seen a large skew by demographic, and samples from third-party data brokers don't report suspected bot activity or unusual app registration patterns on these numbers.

Meanwhile Elon is taking international SMS fraud seriously enough that he's killing SMS 2FA at Twitter, and Facebook seems to be following suit to a degree.

What gives? Are other people also seeing strangeness around T-Mobile users?

  • by surprisetalk on 2/21/23, 10:11 PM

    I got "SIM swapped" on a T-Mobile number even though my account had 2FA protection on it.

    A T-Mobile customer service in another country rep literally gave my number to a hacker because they asked for it.

    I suspect that many of these numbers are SIM swapped.

    [1] https://en.wikipedia.org/wiki/SIM_swap_scam

  • by hd95489 on 2/22/23, 12:40 PM

    T-Mobile numbers are so cheap with unlimited data it’s probably getting to the point that your can pretty easily run scraping off then and they are the new residential proxy of choice.

  • by FrankWilhoit on 2/21/23, 10:01 PM

    Are numbers issued by T-Mobile MVNAs being counted as T-Mobile numbers?