Earlier this week, Russian security firm Dr. Web published a blog post announcing the discovery of a new OS X trojan horse known as "Trojan.SMSSend.3666". The malware masquerades as an installer for various software titles, but tricks users into signing up for subscriptions through their mobile devices.
Similar trojans have affected Windows and even Android platforms for some time, but the tactic is now being used to target Mac users.When a user starts such an installer, they see the interface that imitates the installation wizard of a corresponding application. In order to continue the "installation" fraudsters ask that the victim enter their cellphone number into an appropriate field and then specify the code found in a reply SMS. By performing these actions the user agrees to terms of a chargeable subscription and a fee will be debited from their mobile phone account on a regular basis.
Article Link: Apple Quickly Updates Malware Definitions to Detect New SMS Scam Trojan