SIMhuijaukset

SIM-huijaukset refer to fraud where a attacker gains control of a victim’s mobile phone number by transferring it to a SIM card controlled by the attacker. With this control, the attacker can receive calls and text messages, including one-time passwords and reset links, enabling unauthorized access to online accounts and financial services.

How it works is typically through social engineering or exploiting weaknesses in carrier authentication. Attackers may pose as the victim and provide personal data to persuade a mobile operator to port the number to a new SIM. This can involve data breaches, phishing, or in-person manipulation. In some cases a SIM swap or SIM cloning is used to duplicate the victim’s number across devices, allowing interception of 2FA codes and recovery emails.

Consequences for victims can be severe. Access to banking, email, social media, and other services may be compromised. Funds can be stolen, accounts emptied, or identity details misused. Recovery can be lengthy and may require extensive verification with the carrier and affected services.

Prevention and response focus on strengthening authentication and carrier protections. Helpful steps include enabling carrier PINs or port-out protection, requiring in-person verification for number transfers, using SIM locks or eSIM settings, and prioritizing app-based or hardware security keys for 2FA instead of SMS. If number service is disrupted, contact the mobile operator immediately, secure all online accounts, change passwords, review account activity, and enable alerts. Awareness and rapid response are key to mitigating SIM-huijaukset.