Shit happens. In my case, I was injured in a motorcycle wreck. Been out of commission since the 31st of October. I’m doing a lot better now and am going to finish my reversing sessions when I get home from my parent’s house in AZ.

In the mean time however, I did manage to take a peek at some new anti reversing tricks. Packers, odd instructions and the like are popping up in newer stuff.  Check this instruction out:

UD1-6

It generates an invalid opcode. This instruction is provided for software testing to explicitly generate an invalid opcode. The opcode for this instruction is reserved for this purpose. Other than raising the invalid opcode exception, this instruction is the same as the NOP instruction.

When i get back to town I’ll be sure to detail this one nasty packed exe that makes use of these weird assembly instructions and odd branches.