SIM swapping is a cyber scam where criminals, using stolen personal data and social engineering, trick mobile operators into transferring a victim’s phone number to a fraudulent SIM card. This allows fraudsters to intercept calls and SMS, including banking verification codes, enabling account takeovers. Warning signs include sudden loss of mobile reception and inability to access accounts. Preventive measures include updating software, avoiding suspicious links, limiting personal data online, using strong PINs, and monitoring financial statements. Victims should immediately contact their provider and report incidents to the Police.