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. ...

Little Snitch was among the first software packages I tried to reverse and crack when I started using Macs. In the past I reported some weaknesses related to their licensing scheme but I never audited their kernel code since I am not a fan of IOKit reversing. The upcoming DEF CON presentation on Little Snitch re-sparked my curiosity last week and it was finally time to give the firewall a closer look. ...

My original goal when I started poking around Apple’s EFI implementation was to find a way to reset a MacBook’s firmware password. My preliminary research found references to a “magical” SCBO file that could be loaded onto a USB flash drive and booted to remove the password. The normal process workflow is to first contact Apple support. Since I don’t have the original sales receipt of this specific Mac, I assume this option isn’t possible, since anyone with a stolen Mac could get the password reset. Things got more interesting when I found a website that allegedly sold the SCBO files – just send them the necessary hash (more on this later), pay USD100, and get a working SCBO file in return. There are videos (in Portuguese but you can watch the whole process) of people claiming this works, and even some claims about an universal SCBO that unlocks multiple Macs. ...

The exploit for the bug I presented last March at SyScan360 is today one year old so I decided to release it. I wasn’t sure if I should do it or not since it can be used in the wild but Google Project Zero also released a working version so it doesn’t really make a difference. I’m also publishing here the final version of the slides that differ slightly from the version made available at the corporate blog....