SMS Tracking. How it works
The software application exploits a vulnerability in the SS7 data transmission protocol to hack the history of SMS messages. The peculiarity of this technology is the ability to scale access to the user's database after one of the data packets is hijacked. This is exactly what the VBSpy application uses: The software takes advantage of an authorized Viber account - it requests to restore access to it, intercepts an SMS message with a verification code, and then scales the access gained until the full message history is hacked. Once the hack is complete, the software installs a new SMS tracking pixel on the device and starts tracking.