Researchers at Symantec analyzing the attacks found images were hiding code that enabled communication back and forth with infected machines and a command-and-control (C&C) server. Operation Shady Rat was the name given to an ongoing series of cyber attacks conducted worldwide that affected 70 different corporations over the last five years. McAfee revealed the attack last week following the culmination of an in-depth analysis on one of the attack s C&C servers. Using steganography, the science of writing messages in a way only the sender and intended recipient can see, the attacker encoded encrypted HTML commands into the images.
Source: https://threatpost.com/shady-rat-attackers-hid-code-digital-images-081211/75538/