Apple hired the hackers who created firmware virus for Apple Mac computers. It is the first virus which capable to attack Mac computers through its firmware. The virus is powerful enough which allow it to move from one device to another device without the Internet connection. The virus spread through the hardware peripherals such as the Thunderbolt points, charger cable and Ethernet adapter. If one computer was infected and you borrow the infected peripheral, the virus will be spread to your computer without you notice it.
Luckily, the hackers did not sell the way to do it to the black market. Instead, they inform Apple regarding the issues and Apple already patched it. Today, they officially announced that they start working with Apple and their current job is to improve low-level security. It is unknown whether it is for Mac or iPhone. Maybe they are working on next Apple HomeKit?