Cybercriminals are constantly prowling the depths of cyberspace in search of victims to attack. The motives for their attacks vary: some cybercriminals deface government websites to make political statements; others spread malicious software to do large-scale harm; and others still are monetary motivated. In this paper we will concentrate on “cyber fraudsters”. At the time of this writing, a prime hunting ground for fraudsters is online banking. Millions of people worldwide use online banking to quickly and conveniently do their regular bank-related transactions. Unfortunately, this convenience comes at a price. By doing their banking online, they are vulnerable to falling prey to fraud scams such as SIM swap fraud. This paper explains what SIM swap fraud is and how it works. We will analyze the online banking payment transaction process to discover what vulnerabilities fraudsters exploit via SIM swap fraud, and then introduce a computer-based security system which has been developed to help combat it.