SIM card fraud is a type of cybercrime where attackers use stolen, cloned, or bulk-purchased SIM cards to impersonate legitimate users. This allows them to bypass security controls, create fake identities, and carry out malicious activities such as account takeovers, phishing, or financial fraud. Criminals may exploit vulnerabilities in mobile carrier processes or use social engineering to convince providers to transfer a victim’s phone number to a SIM card they control. This can lead to unauthorized access to sensitive accounts, interception of authentication codes, and significant financial or reputational damage for victims. Preventing SIM card fraud involves using strong authentication, monitoring for suspicious activity, and educating users about social engineering risks.