Are you targeting the BIOS or the OS? Are you targeting it during boot
   or while running?

   I suppose targeting the BIOS would be cool. I guess it'd be easier to
   (through booting the pendrive) write your malware to the OS.

   I'd suggest replacing the default keyboard drivers with your own
   special flavor. In case of signed drivers you have a problem. Maybe you
   can modify the OS's routines for checking signatures.

   The lamer method would be getting some malware for Mac and some for
   Linux and placing everything in the right folders. Similar but
   different.

   Still you're only targeting OSs, never all OSs.

   You could instead target only BIOSs or UEFIs. Your choice.

   2013/8/8 Yush Bhardwaj <[1]yushbhardwaj91@gmail.com>

   Guys I was trying to setup a pendrive as malware which works for all OS
   (Windows/Linux/Mac).
   I know how to do it for windows but I am still searching to get my
   setup done for mac and linux.
   Any her knows anything about it
   Yush Bhardwaj

References

   1. mailto:yushbhardwaj91@gmail.com