Originally Posted by Hyolyn
Everything that is being reported is possible...well, it is questionable about the sound equipment working outside of normal human hearing. I was going to setup a demo of transmitting data by sound, but it is a very well documented procedure and before the days of proper networking it was actually used in many cases instead of a serial connection...and truth be told I just didn't have time.
However, I did test various frequencies to see if my speakers and mic could pick them up since that is really the only thing I question at this point. I discovered there are many frequencies that even if I get activity shown or heard on my speakers...the mic would not pick it up. This isn't high quality audio equipment, well, better than average or what you'd find built into most laptops I suppose. I just downloaded some high pitched wav files and used the dog whistle videos and such. I could not get my mic to show any activity at anything over 15,000Hz. Note that I could still barely hear the sounds at 15,000Hz., but the mic could not. My speakers did not not seem to handle anything higher than 24,000Hz correctly. I could hear it and I doubt I have super hearing. I am guessing in trying to play a sound they were not able to they made a sound at a much lower frequency.
The only other bogus thing about this is that a computer security professional has been working on it for three years without discovering it. I find that hard to believe. It should be fairly easy to spot a process that is using the sound services...as it would have to use it. Unless it was somehow masking itself...but that is typically easy to spot because a oddball service will be running to do the masking. If it was originating in firmware or the BIOS it should be a simple process to dump what is there and compare it to what it should be...when dealing with kilobytes you can look at them block by block in a short time. I also think this hole thing was a waste of time. It is just another BIOS virus...and methods to prevent other BIOS viruses will probably work on this one as well.