The first thing which typically happens, said Vermooten, is that an Internet banking client falls for a phishing attack. This gives the scammer access to a client’s Internet banking details, including their username and password.
To find a victim’s mobile number is easy, said Vermooten. A good search typically does the trick, and if that is not successful social media is another great tool.
I have not used ABSA's Internet Banking for many years but I would have thought that the fraudster who allegedly already has the victim's IB username and password, could simply view the IB page where one would normally update one's address and contact details as well as SMS alerts, to find the victim's cellphone number.