Circlean

But it's the assumption that is in itself inaccurate. Case #1 is about a modified firmware of the USB controller in the USB stick, case #2 assumes that a boot is initiated from the USB stick. What the Circlean thingy does is more similar to an antivirus, it examines the contents (files) on the USB stick filesystem and only copies to the second stick those files of known type, according to the given rules. Whether this is effective against everything is another thing, of course. Only "plain" files are directly copied, other supported ones are analyzed and converted, some more detiled info is here: https://github.com/CIRCL/Circlean/blob/master/README.md The thing is not really "new": https://news.ycombinator.com/item?id=8216853