Sujet : Think You're A Programmer? Think Again.
De : ff (at) *nospam* linux.rocks (Farley Flud)
Groupes : comp.os.linux.advocacyDate : 13. Apr 2024, 17:21:53
Autres entêtes
Organisation : UsenetExpress - www.usenetexpress.com
Message-ID : <17c5e02c1c64d208$662$181469$802601b3@news.usenetexpress.com>
Any TRUE programmer can also program in reverse, i.e. de-program.
Let's see if you can assist the global effort in documenting the
xz-backdoor.
GNU/Linux has the absolute best tool for the job: Ghidra.
https://ghidra-sre.org/I have posted an image of the xv-backdoor loaded into ghidra
and analyzed:
https://i.postimg.cc/NsrmMvDv/xz-backdoor.pngThe left panel shows the dissassembled code and the right shows
the corresponding de-compile.
Notice the match:
xor edi, edi
mov esi, 0x12
mov edx, 0x46
mov ecx, 0x02
CALL .Llzma_decoder_end.1 <==> iVar4 = .Llzma_decoder_end.1(0, 0x12, 0x46, 2);
TEST EAX, EAX
JZ LAB_00100606 <==> if (iVar4 == 0) {
Ghidra is fucking fantastic!
Unfortunately, I will not be attempting to document the backdoor.
To do so would entail first learning thoroughly the functions of
sshd and I am not at all interested in network programming.
Yes, sshd. Did you think that the xz-backoor was about compression/
decompression? Ha, ha, ha, ha, ha, ha, ha, ha, ha!
Think again.