A few weeks ago, Copycat sent me an email asking if I knew anything about the TNT warez group macOS cracks. They were worried that the cracks could be used to leverage malware since TNT is (?) Russia based. Cyber war is real and this could be an interesting case to look at. These cracks are based on a dynamic library injection, with obfuscated code and anti-debugging measures. This of course triggered my curiosity since the usual anti-anti-debugging measures (ptrace & friends) weren’t working. Even more interesting, one of the cracked apps had pro-Ukraine related content that was modified, so it was a perfect target for malware. Even if malware free, what was behind the obfuscation and anti-debugging? ...

Flare-On 2024 is gone and I just made a presentation about the challenge #5 at the local meetup called 0xOpoSec. I think it’s a nice challenge to introduce a few RE and forensics concepts, and a perfect candidate to present this year. The slides are available here, and the Unicorn Engine emulator I used to extract the flag from the final shellcode here. Last year I did the same with challenge #12, also with a Unicorn Engine emulator....

I apologize if this information is already known, but I couldn’t find any references about it and I wanted to understand what was going on and share with you because I think there is some value doing it. In case this wasn’t known, I apologize to the Go team for not talking to them first and jumping the full disclosure gun (I don’t think it’s that severe). I really like Go!...

Note: the original post was written in 2017 when there weren’t many posts discussing direct attacks to firmware flash. It also took a while to get in touch with the ISP to give them a chance to fix some of the issues described (in particular the ACS access) and then it was left in draft mode until today. I just made a quick revision and fixed quite a few dead links....

Back in 2017 (feels like ages ago) I decided to take a peek into the ShadowBrokers leaks and reverse some of the tools. I started on dewdrop simply because it had a macOS version. I made local presentations at 0xOpoSec and BSidesLisbon but those slides were never published for obvious reasons (aka live implants all over the Internet). Significant time has passed and everyone went crazy last week with the beautiful NSO exploit VM published by Project Zero, so why not ride the wave and present a simple NSA BPF VM. It is still an interesting work and you have to admire the great engineering that goes behind this code. It’s not everyday that you can take a peek at code developed by a well funded state actor. This post is only going to focus on the BPF part of the implant so you will have to fill in the blanks about everything else. ...