Hacker News Reader

Comment by hinkley | Hacker News Reader

I don't know why but this reminds me of a story I read long long ago about someone figuring out that the local Big Box store had their PA system attached to a phone number. You could call in and say anything you want.

They kept up the ruse for quite a while by being subtle at first with their mischief.

View on HN

Apparently, that's pretty common:

Target: http://www.bbc.com/news/technology-34556644

Fred Meyer: http://www.phonelosers.org/zine/pla025/

General Info: https://www.mattwilson.uk/2015/12/16/stores-pa-systems-attac...

Heh. This brings back a lot of memories. I got into a whole world of trouble as a teenager in the summer of 1998 when a friend and I, a couple of bag boys learned how this worked.

Hilariously enough? I work for a telecom startup now.

Thanks for the trip down memory lane :)

I'm giggling like a teenager over this. Easily the second best part about being a teen were the pranks.

Telephone-based door intercom systems unlock the door in response to a DTMF tone from the "inside" line. This means that control over call forwarding for any of the relevant extensions is as good as a key to the building.

Good thing no one ever leaves their PBX connected to the internet with a default admin password. Or puts edit access to their voicemail greeting behind a PIN like 1234# or 0000#.

How do these system avoid robocalls and the like?

I'm curious about this as well.

Though at a previous job, I got on the elevator one day to hear a telemarketer's voice coming from the emergency speaker. I'm guessing it happens, but just very rarely?

In the case of the Target breech one had to be transferred to the unlisted extension first. So it's not as though it's a phone number exposed to the outside world.

I had something similar, twice. Once I was in the elevator when the emergency phone started ringing. I picked up, and it was the Seattle Times trying to sell subscriptions.

The other time, same elevator, it was someone asking for a specific person that I had never heard of.

Maybe you have to press a DTMF digit first, something the robocalls wouldn't know how to do? (and have no incentive doing, as so far nobody is using this to block robocalls; I'd expect them to catch on if this kind of "firewall" starts being in widespread use)

During the last presidential election I received a robocall in an elevator of then-candidate Trump screaming about immigrants. I heard a ring tone and then the elevator picked up automatically. Our emergency phones ring regularly. I have answered them several times and it always sounds like a scammer on the other end.

I think the answer to your question is "they don't".

Reply on news.ycombinator.com