Gatekeerper – A kernel extension to mitigate Gatekeeper bypasses

Last month Patrick Wardle presented Exposing Gatekeeper at VB2015 Prague. The core of the presentation deals with Gatekeeper bypasses originating in the fact that Gatekeeper only verifies the code signatures of the main binary and not of any linked libraries/frameworks/bundles. This means it is possible to run unsigned code using dynamic library hijacking techniques also presented by Patrick in code that should be protected by Gatekeeper. His exploit uses an Apple code signed application that is vulnerable to dylib hijacking and is modified to run unsigned code when downloaded from the Internet....

November 9, 2015 · 12 min · 2463 words

London and Asia EFI monsters tour!

Finally back home from China and Japan tour, so it’s time to finally release the updated slides about EFI Monsters. After Secuinside I updated them a bit, fixing stuff I wasn’t happy with and adding some new content. The updated version was first presented at 44CON London. I had serious reservations about going to the UK (not even in transit!) but Steve Lord and Adrian charm convinced me to give it a try....

November 6, 2015 · 3 min · 498 words

Rootfool – a small tool to dynamically disable and enable SIP in El Capitan

El Capitan is finally released and System Integrity Protection aka SIP aka rootless is finally a reality we must face. Let me briefly describe SIP (technical details maybe in another post, now that El Capitan is final and out of NDAs). This post by Rich Trouton contains a very good description of its userland implementation and configuration. What is SIP anyway? The description that I like to use is that SIP is a giant system-wide sandbox, that controls access to what Apple considers critical files and folders....

October 12, 2015 · 6 min · 1165 words

Writing Bad @$$ Lamware for OS X

The following is a guest post by noar (@noarfromspace), a long time friend. It shows some simple attacks against BlockBlock, a software developed by Patrick Wardle that monitors OS X common persistence locations for potential malware. The other day noar was telling me about a few bypasses he had found so I invited him to write a guest post. The title is obviously playing with one of Patrick’s presentations. I met Patrick at Shakacon last year and this is not an attempt to shame him (that is reserved mostly for Apple ;-))....

August 7, 2015 · 5 min · 984 words

BSides Lisbon and SECUINSIDE 2015 presentations

I guess my goal for the remaining 2015 of not doing any presentations will not happen. Two weeks ago I presented at BSides Lisbon 2015 and last week at SECUINSIDE 2015. I’m very happy to see BSides Lisbon returning after the first edition in 2013. Congrats to Bruno, Tiago, and the rest of the team for making it happen. It’s still a small conference but I’m glad they are making it happen, and I will always do my best to help the Portuguese scene going forward....

July 21, 2015 · 2 min · 425 words