IRSF (International Revenue Share Fraud)

International Revenue Share Fraud is a scheme in which fraudsters generate calls or SMS to high-cost premium destinations (often international premium-rate numbers under their control) and pocket a share of the resulting termination charges. The traffic is typically generated by compromised PBXs, abused trial accounts, or SIM-box fraud. IRSF causes hundreds of millions in annual losses; controls include fraud-management systems with machine-learning detection, real-time call-rating thresholds, and number-range blocking.

Categories: Radio Access NetworkIdentity and SubscriberThreats and Attacks

IRSF in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Subscriber identifiers (IMSI, SUPI, MSISDN, IMEI) are the anchor for authentication, charging, lawful interception and fraud analytics. Any protocol or interface that leaks a permanent identifier is treated as a serious privacy defect, which is why 5G introduced SUCI concealment on the air interface.

To place IRSF in the wider telecom-security picture, review Wangiri Fraud, IMEI, Artificial Traffic Inflation, Malware, SIMBox Fraud and SMS Pumping.

Related terms

Related topic hubs

  • Telecom Fraud IRSF, Wangiri, SIM box, PBX hacking and CLI spoofing.
  • Diameter Security 4G/LTE Diameter threats across IPX/roaming and DEA defenses.
  • Diameter Attacks S6a IDR/PUR/CLR abuse, subscriber tracking, LTE signaling attacks.
  • SMS Firewall SMS spam, phishing, A2P bypass and MAP-layer SMS filtering.

More from the TelcoSec Glossary

Browse the full TelcoSec Glossary, the Ultimate Guide to Mobile Network Security, or the P1 Arsenal of telecom-security tools.