A SIM swap attack is a cunning form of social engineering that exploits a mobile carrier's service to port phone numbers. In this scheme, attackers hijack a victim's phone number by transferring it to a SIM card they control. This seemingly simple switch grants them access to a treasure trove of potential targets, often bypassing robust security measures.
The attack hinges on gathering personal information about the victim. This data can be stolen through phishing scams, data breaches, or even social engineering the victim directly. Armed with this information, the attacker impersonates the victim by contacting the mobile carrier's customer service. Using stolen personal details and persuasive tactics, they convince the representative to authorise a SIM swap, effectively linking the victim's number to the attacker's SIM card.
Once the swap is complete, the attacker intercepts all calls and texts, including crucial Two-Factor Authentication (2FA) codes. With these codes, they can bypass login security and gain access to the victim's online accounts—email, bank accounts, social media, and anything else linked to the compromised phone number.
The success of a SIM swap attack relies on the attacker's ability to impersonate the victim convincingly. However, there are also cases where compromised carrier employees are bribed to facilitate the SIM swap directly.
While seemingly simple, SIM swap attacks underscore the importance of layered security. By employing strong passwords in conjunction with 2FA methods that go beyond SMS verification (like app-based authenticators), organisations and individuals can significantly mitigate the risk of falling victim to this deceptive scheme.
