A new type of malware that is using sound to transmit itself has been developed by scientists and it seems that the Linux systems are the only ones that can be protected against this kind of attacks.
Scientists Michael Hanspach and Michael Goetz from Fraunhofer FKIE, Wachtberg, Germany, have developed a technique capable of infecting other computers with malware that transmits itself using just speakers and microphones.
“Covert channels can be used to circumvent system and network policies by establishing communications that have not been considered in the design of the computing system. We construct a covert channel between different computing systems that utilizes audio modulation/demodulation to exchange data between the computing systems over the air medium,” reads the paper that they published in the Journal of Communications.
This would prove a very powerful method of infecting computers, especially because they don't even have to be linked in a network. All that is needed for the method to work is proximity.
Another problem is that there is virtually no protection embedded in today's operating systems for such malware. The good news is that Linux users can make a few small modifications in order to gain that much needed protection.
The developers have explained that Linux systems can be programed, rather easily, to adapt to this new form of attacks.
“If audio input and output devices cannot be switched off, implementation of audio filtering options may be an alternative approach to counter maliciously triggered participation in covert networks. “
“In Linux-based operating systems, a software-defined audio filter can be implemented with ALSA (Advanced Linux Sound Architecture) in conjunction with the LADSPA (Linux Audio Developer’s Simple Plugin API),” the scientists say in the paper.
Sound-transmitted malware is something very new and it's no wonder that there is no protection against it, but it goes to show why Linux systems are considered safer.