thinQmaster Virtual testing partner Adaptive practice exams that find your weak spots and drill them. Every answer explained. From $69
Enroll

thinQmaster

Find your exam

Five questions free, before you decide.

Step 1 · choose a vendor

In one of our camps? Your practice exams come with the tuition — they are on your study page already.

Collaboration, Voice & AV · Intermediate

Toll Fraud

Unauthorized use of a telephony system to place calls, usually expensive international or premium-rate calls, at the owner's expense.

Definition

Attackers exploit open SIP trunks, weak voicemail PINs, auto attendants that allow outside transfers, and poorly restricted CSSs to make calls billed to the victim. Mitigations include restricting inbound CSSs, blocking international and premium patterns, voicemail PIN policies, CUBE's trusted IP list and authentication on SIP trunks. Monitoring CDRs for unusual call patterns helps detect it.

Example

Attackers scan the internet for open SIP gateways and send INVITEs to international numbers through an unprotected gateway.

Exam tip

CUBE rejects SIP from unknown sources unless they are in dial peers or ip address trusted list; do not disable this to fix call failures.

Related terms