Some of the functions and protocols are explained in this earlier presentation at Hack.lu It is also important here to read how one gets information from an internetblocked computer (with probably highlevel information) to an internetconnected computer in a network. The extraction methods are also interesting because in Belgacom the extracted information was encrypted and went for that reason undetected as encrypted traffic was maybe just like in many network trusted - especially if they come from inside the network.
We know that the Regin files by Symantec are not complete and that they only have part of all the files.
Inside the Snowden files you find documentation about a bootkit that also works on Linux because it attacks the hardware and not the software on the machine. (This is why it is important to encrypt all the free room on your harddisk so you can't normally install nothing new on the machine - or not without alerting the securitystaff if you have installed those eventloggers).
So it is not clear at the moment if there are Linux files somewhere. We know by now that it is not hard to take total control over a the root and boot of a Linuxserver and several viruses doing exactly that (and through USB in Apple) have done the rights the last couple of months.
We know that the Microsoft Regin files had several urgent updates (2008 - 2011) and we know that there have been rumours about problems and infections and not being sure of the data of infection well before the official data that Microsoft officially said it was an infection when they came finally to examine the troubled mailserver. We know that the Regin files had a 32bits version and a 64bits version and that around that from 2011 onwards many organisations and industries were moving to 64bits only (to kill all the 32bits viruses in one upgrade). This change has also an impact on the access to the root and may explain the problems. The Snowden files talk about 2008 as the data of penetration (which is also the first set of files).
We know that the Reginfiles had falsified Microsoft certificates or signatures of some files and that for those for which that wasn't possible they posed as a help file of an official Microsoft file in the kernel-root and had access to the root through this helpfile who had access to the kernel-root file. We know that in Belgacom they were talking about Microsoft signed files. This poses in fact huge problems for Microsoft and the way in which it wants to certifiy the files that are written by Microsoft and that are certified by Microsoft.
We know that the Belgacom operation was an intelligence operation and that only very limited information was effectively transferred as the datafiles were small (which was astonishing) It could be that they had larger files at the start of the operation (to have a list of all the employees or of the infrastructure) but as nobody is sure about the data of the first infection there is no way to be sure. As the GRX routers for the GSM traffic throughout the BICS-Belgacom network were the target, we presume it was the metadata for certain high profile GSM numbers that were on the terrorist target list. It is so no wonder that the software that is used in such an operation is built by spies for spies to be able to.... spy.