Spam advertisements usually include a call-to-action, such as a phone number or web address to click on. Driven by click-through rates, the spammers engage in a multitude of techniques to bypass an operator’s systems to reach the subscribers for as low a cost as possible.
The use of SMS as a two factor authentication medium is commonplace as all handsets globally support this method, thus providing a cheap and universal method to secure accounts. Unfortunately, the attackers may masquerade as the business (bank, social media, etc.) or government agency and attempt to retrieve subscriber private information to defraud them.