Mac-based security threats jumped in 2011, but still remain far below that of Windows PCs. F-Secure Labs’ Threat Research team detected 58 unique variants from April through December. Nearly half, 29, were Trojan-downloaders, a type of Trojan horse program that secretly downloads malicious files from a remote server. The second most common threat category, with 15 detected, was backdoors, or remote administration utilities that are designed to slip past security mechanisms to secretly control a program, computer or network.”]
Source: https://www.csoonline.com/article/2130605/apple-mac-based-security-threats-jumped-in-2011.html