We had something similar a few months ago. One of our clients' disconnected TFNs started getting upwards of 30,000 calls per hour.
Didn't bother us too much, but the upstream carrier got a little flustered by so many non-connected calls. We are the RespOrg for the number so we cleared the CICs in SMS/800 and got the spam calls to stop. Calls were not connecting so I don't know what the attacker was trying to accomplish, but there was no way to stop/block the calls other than clear the CICs. The ANIs were spoofed... our client was lucky the number was not active so we could clear the CICs. If the number was active, I am not sure what they/we would've done. As Philip said - the competitors and the carrier benefit in this scenario. Since the cost of committing the crime is so low and it's easy to spoof ANIs, it's difficult to preclude this type of attack. The upstream carrier has involved their fraud department, and theoretically they should be able to trace where the calls came from, but I am not holding my breath. Best Regards, Ivan Kovacevic Star Telecom | www.startelecom.ca | SIP Based Services for Contact Centers -----Original Message----- From: Philip Mullis [mailto:[email protected]] Sent: Sunday, April 20, 2014 5:07 PM To: Bruce N Cc: asterisk Mailing Subject: Re: [on-asterisk] Toll-free attacks? The provider benefits from these type of attacks. Also competitors of a target company have also known to take joy in racking up a competitors bill. If you finding there from a consistent set of numbers or anonymous filter or drop accordingly. On Apr 20, 2014 4:44 PM, "Bruce N" <[email protected]> wrote: > Happy Easter / Spring to ya'll. > > Has anyone seen a drastic increase on their toll-free inbound calls > which results in high charges from provider? > > Is this a new type of attack? Who might benefit from this type of > attack and how to mitigate it? > > - Bruce > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
