My company, Talia, provides hosted Voice-over-IP (VoIP) services to our customers. A typical use is a software-based PBX such as Asterisk on our virtual machine hosting cluster (or as the kids say, our “cloud”). We use the same for our own corporate PBX.
In the past month, we’ve experienced two fraudulent attacks costing a few hundred USD each. We have measures to detect and prevent such things, but that’s not what I want to talk about. I want to talk about how these attacks occurred.