Tools

Some time ago a friend received a mysterious USB pen with a note talking about some kind of heavily persistent malware. He had that USB pen stored untouched and of course my curiosity took over. Since one should never plug in unknown USB devices into a computer (well, any USB device we purchase is unknown but that is another story) and I didn’t want to “burn” a computer just to take a look at the contents I decided to use my USB armory to build an air gap sandbox that would be harder to infect and for malware to escape from it. ...

Today I am finally releasing one of the EFI reversing tools I built when I was working on the SCBO post. Yesterday there were some tweets about IDA improving its support for EFI binaries (although I’m not sure it’s the same thing as in here) so I decided to finally release this one. ...

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....

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....

Let me present you another TrustedBSD policy module, this time to control execution of suid enabled binaries. The idea to create this started with nemo’s exploitation of bash’s shellshock bug and VMware Fusion. It was an easy local privilege escalation because there are many Fusion suid enabled binaries. This got me thinking that I want to know when this kind of binaries are executed and if possible control access to them....