Wangiri fraud
Wangiri — the one-ring callback scam.
Wangiri, Japanese for "one ring and drop", is a mass callback scam. It turns curious subscribers into revenue for fraudsters operating premium international numbers.
The scheme
How Wangiri works
Fraudsters place huge numbers of very short calls from premium-rate international numbers, hanging up after one ring. A small percentage of people call back, assuming they missed something important. Each callback is billed at a high international rate, and the fraudster collects a share of the termination revenue — the same economics as IRSF, aimed at consumers instead of PBXs.
Campaigns are cheap to run and profitable even at tiny callback rates. Terminating carriers feel it as subscriber complaints and billing disputes; originating and transit carriers feel it as a reputation and compliance problem.
Detection
The signals that give Wangiri away
Ultra-short attempts
Campaigns are dominated by attempts that ring for a second or two and then cancel, with almost no answered calls.
Huge fan-out
One source reaching thousands of different numbers in minutes — something legitimate traffic rarely does.
Risky origins
Calling numbers cluster in a handful of international ranges with weak oversight.
How VoIP Radar stops Wangiri
VoIP Radar recognizes Wangiri fan-out patterns as they happen and blocks the source before the campaign reaches significant numbers of subscribers. It also watches the other side of the scam — sudden waves of outbound callbacks to high-risk destinations — so revenue leaks are caught quickly and affected subscribers can be warned.
Get in touch
Find out where your network stands
Tell us about your switch and traffic. A VoIP Radar engineer will map your STIR/SHAKEN, RMD and fraud exposure and send a written assessment — free, within one business day.
- STIR/SHAKEN & attestation review
- RMD certification gap check
- Fraud & robocall exposure snapshot
- Deployment plan for your SBC / softswitch