lostpwagain
I'm not sure if these types of units usually dive that deep that you would be worried about brain damage, but I'm less familiar with that side of things. Diving probably hasn't been that much of a focus during the recent years in the middle east either.
At the same time, this attempt nicely illustrated that the chain is only as strong as the weakest link since, as I understand it, no part of the backdoor was committed to the git repository in cleartext. Instead, the part of the backdoor that was at least somewhat identifiable was only included in the tarballs that would be downloaded and used by Debian/Fedora when building the packages for these distributions, thus giving a very nice trade-off between the chance of someone detecting what was going on and the potential impact of the backdoor.