SIM Swapping Attacks: Mechanisms, Identity Takeover Pathways, and Forensic Countermeasures in Modern Telecom Networks

Due to the ubiquity of mobile devices for digital identity verification, SIM swapping has emerged as an unintended high-stakes vector for cybercrimes. With the advancement of telecommunications technology from GSM to 5G, reliance on the Subscriber Identity Module (SIM) for two-factor authentication (2FA) has become a critical vulnerability. In this paper, fraudsters employ a variety of techniques, ranging from social engineering to technological exploitation, across both traditional and contemporary network infrastructures. We investigate identity takeover methods that circumvent traditional security mechanisms and cause significant financial and personal losses. In addition, this study assesses telecom infrastructure weaknesses where unique vulnerabilities of GSM, LTE, and UMTS interworking exist, and covers new attacks, including AdaptOver. Eventually, we propose a model for forensic countermeasures and mitigation by focusing on location-based verification, devicespecific authentication binding, and increased ceremony modelling to protect subscriber identities.