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

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

To place IRSF in the wider telecom-security picture, review Cell Phone (Mobile Phone), CPE, Firmware, IMEI, Malware and Paging Attacks — each entry cross-references back to this page so you can walk the topic in either direction.

Related terms

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