Advanced Detection and Mitigation of Rogue Base Stations Using RayHunter & a Rooted 4G Hotspot

////////////////////////////////////////////////////////////////////////////
// As mobile networks become increasingly sophisticated, so do the tools  //
// and techniques used by adversaries to exploit them.                    //
//                                                                        //
// Rogue base stations, also known as IMSI catchers or stingrays,         //
// pose a critical threat to mobile networks. They are capable of         //
// intercepting communications, tracking devices, and even launching      //
// denial-of-service attacks.                                             //
//                                                                        //
// Tools like RayHunter are invaluable for detecting such threats         //
// by analyzing LTE paging messages and other signaling activities.       //
////////////////////////////////////////////////////////////////////////////

Rogue Base Stations: The Threat

A rogue base station masquerades as a legitimate cell tower, tricking nearby devices into connecting to it. Once connected, these devices can be exploited in several ways: ------------------------------------------------------------------------------------- - IMSI Harvesting: Requests devices to reveal their IMSI, compromising user privacy. - Tracking and Surveillance: Tracks devices' movement using temporary identifiers like m-TMSI or identifies repeat users. - Data Interception: Intercepts and manipulates traffic, compromising sensitive communications. -------------------------------------------------------------------------------------

How RayHunter Helps

RayHunter monitors and analyzes LTE traffic, providing visibility into critical signaling activities. It identifies the fingerprints of rogue base stations by detecting patterns such as: +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [1] Unusual Paging Patterns: Rogue stations generate atypical paging requests (e.g., frequent/simultaneous paging). [2] Suspicious MMEC and m-TMSI Values: Legitimate base stations frequently randomize these, but rogue stations may fail to. [3] Anomalous Signal Levels: Rogue stations often overpower legitimate towers with stronger signal levels. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

MMEC and m-TMSI in Detection

MMEC (Mobility Management Entity Code) - What It Is: Identifies the MME managing a device. Each legitimate network operator has a predictable range of MMEC values. - Rogue Station Red Flag: Detection of MMEC values outside the operator's range may indicate rogue activity. m-TMSI (Temporary Mobile Subscriber Identity) - What It Is: A temporary identifier used to protect IMSI over the air. - Rogue Station Red Flags: * Static or reused m-TMSI values over time (failure to randomize). * m-TMSI values inconsistent with MMEC (illegitimate pairing).

Example from RayHunter

Captured messages from RayHunter flagged anomalies: >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> [+] MMEC: c3 (195), m-TMSI: c4685385 (3295171461) [+] MMEC: 8c (140), m-TMSI: c2891c10 (3263765520) >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Conclusion

Rogue base stations represent a significant threat to user privacy and network security. Tools like RayHunter provide invaluable insights by analyzing LTE paging activity, particularly patterns in MMEC and m-TMSI values. By leveraging these tools, mobile security engineers can detect and deter rogue base stations, ensuring safer mobile environments for users.