Scam calls from rotating numbers - T-Mobile USA

I’ve been getting a lot of spam/scam calls lately. 20 or so in the last 36 hours, 10 of those within the last couple hours. They are coming from various numbers, so blocking each one is not 100% effective. I’ve been blocking them anyway, using both YACB and the /e/ OS Phone app (the former because it’s easier to backup and restore the blocked number database, and the latter because well, I don’t know).

Some of these leave voicemails with a robotic voice, saying: “(unintelligible) do you recognize this attempt? If this was not you press one if this was you press two.”

I called T-Mobile USA and they said to install the Scam Shield app. I don’t see this in the App Lounge (using an anonymous login).

I also tried dialing #662 to enable “Scam Block” following instructions on Help with scams, spam, and fraud but I’m still getting these odd, seemingly related calls.

Any ideas?

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The attack (or whatever it was) seems to have abated. I guess going “do not disturb” and just waiting it out is the way to go.

Here’s (part of) a flurry of calls (just as many as will fit in one screenshot) from about an hour ago:

Many of them left voicemails, always with the same message. I had about 15 in my inbox.

Note how none of the numbers are known to YACB. Usually I see something like “Telemarketer” and a red thumbs down when I’m getting a spam call.

I found the T-Mobile Scam Shield on apkmirror… is that a trustworthy site? Seems sketchy to side-load an APK like that, and I probably won’t unless I get overrun by more of these rotating-number call blasts.

Here’s a list of the numbers:


I submitted a few to (the service YACB uses).

For U.S. residents, here are some additional measures to take:

1_ Make sure you’ve registered your phone number(s) at
2_ At the same site, you can report numbers of any violators.
3_ If you also start getting spam texts, forward the texts to 7726 (which spells SPAM).
4_ For political/campaign texts, just reply STOP. (They’re unfortunately authorized to send canvas-texts until you tell them to stop.)

From what I’ve read, the FCC is cracking down on networks that don’t implement [STIR/SHAKEN]( Those networks are usually VOIP infrastructure providers that make large blocks of virtual numbers available to businesses, some of them legitimate. Unfortunately, they attract a lot of shady scammers, also… including overseas-based operations (with spoofed U.S. numbers) that may be difficult to hold accountable.

You can figure out which network is the provider for the robo/scam/caller by checking them on a site such as (Caution: Facebook and Google trackers there). The provider will usually be one of the major or obscure VOIP infrastructure providers. (The aforementioned site doesn’t provide info for toll-free numbers, but there are other sites that do.) This helps you determine whether a calling number might be a telemarketer/scammer (using providers like Sinch, Telnyx, etc.), versus a legit caller on, e.g., T-mobile, AT&T, Verizon, etc.

Good luck!


Regarding YACB, have you been blocking numbers individually?
Using wildcards will block numbers in groups.
Like +18886* will take care of any in that group.
+17167* will deal with another, etc.

My main number (VoIP but ported from T-Mobile) has been getting a constant, daily from a +1760 set but YACB has that handled.

Just realized that I used to get a lot from China based numbers (+86) but none since October.
Maybe a result of the crackdown(?).