Tales from Crisis, Chapter 2: Backdoor’s first steps

Let’s continue our cute story about OS.X/Crisis, this time with the startup flow of the main backdoor module. Please apologize for the delay on this chapter – I had some fun with the rootkit and that diverted me to other things. The first curious detail about the backdoor module (installed as /Users/USERNAME/Library/Preferences/jlc3V7we.app/IZsROY7X.-MP) is that no obfuscation/anti-debugging tricks are used (except one) so its analysis is easier than the dropper. It also uses Objective-C heavily, which is still a bit annoying in IDA but has the advantage of the code being very descriptive....

August 20, 2012 · 8 min · 1635 words

Tales from Crisis, Chapter 1: The dropper’s box of tricks

Mac malware is back to news spotlight, this time with Crisis (insert one of the other thousand names here _____). This malware is nothing more than commercial spy software being sold by a lot of money to governments or something (oh boy, I could make a good living out of this). I’m lucky enough to have a sample of it (thank you, you know who you are!) and also lucky to be able to talk about it (it uses some similar tricks that I knew about)....

August 6, 2012 · 6 min · 1236 words

"Sandwich" CrackMe tutorial by qwertyoruiop

This is a cracking and keygen tutorial by the reader qwertyoruiop. He’s having fun doing the crackmes and I asked him to write tutorials about them and he did it! So here it is the first in full glory. Things been quiet around here but busy in real life. I wanted to write a few posts about OS X malware but I’m going to present at a conference in July on that topic (hopefully something interesting!...

June 4, 2012 · 1 min · 96 words

Dynamic Code Encryption in OS X: the crackme example!

The title of this post is a partial rip-off of Dynamic Code Encryption as an Anti Dump and Anti Reverse Engineering measure blogpost. Alexey describes a technique similar to the one I used in my crackme, which isn’t altogether that new. His post is a good introduction to some possible attack vectors and what is at stake. You should give it a look. The crackme uses a multi-layer dynamic code encryption approach, with two different encryption algorithms (Rabbit and Salsa)....

March 17, 2012 · 6 min · 1125 words

AV-monster: the monster that loves yummy OS X anti-virus software

Welcome to another “silly” evil idea that abuses bad design decisions, bad implementations and lazyness. It is the last of my ideas in a state of semi-disclosure so let’s move it to full disclosure status. The full disclosure discussion will probably never end. There are too many interests at stake, mostly in opposite directions. For me it’s worrisome that (security) products are available with notorious design/implementation flaws which put customers at risk and fail on their purpose....

February 13, 2012 · 5 min · 1009 words