This week I got the CREA certification to add to my list of CISSP, CEPT, Visa QSA. This certification required a good practical and conceptual knowledge of reverse engineering. The certification requires a good working knowledge of components such as IA-32 assembly language, malware reversing, expert level knowledge of IDA Pro, OllyDbg, HiEW, Dumpbin etc., PE File header, repairing packed and compacted binaries, using system level reversing etc. The exam was good and tested on the concepts of the reverse engineer.

I’ve been struggling to find the best working version of John so that it can crack MS Cache outputs from Cachedump (of course, this functionality is now included in fgdump). Running fgdump gives two files host.pwdump and hostname.cachedump. I’ve found 127.0.0.1.pwdump and 127.0.0.1.cachedump files upon using fgdump without any parameters.
So now you have the Cached credentials but then comes the big problem of cracking those. So there’s the jumbo patch for john-1.7.2.
Following commands need to be executed to get this patch going:

$ tar zxvf john-1.7.2.tar.gz
$ cd john-1.7.2/
$ wget http://www.openwall.com/john/contrib/john-1.7.2-all-9.diff.gz
$ gzip -d john-1.7.2-all-9.diff.gz
$ patch -p1 <john-1.7.2-all-9.diff
$ cd src/
$ make linux-x86-sse2

You get some warnings upon compilations but the executable works very well.

Go ahead and get cracking:
$ cd run/
$ ./john –format=mscash

So the other day I was on a pen test and I got hold of the hashes. Since my laptop got fried I needed a new version of SMBProxy. There were a few issues that I had with the compilation though. I got a few errors in the file crypto.c.
Moreover, SMBProxy ues crypto library libdes written by Eric Young available here.
I give here a guide to compiling SMBProxy that worked for me.

First, compile and install libdes

1. Download libdes 4.01
2. tar zxvf libdes-4.01.tar.gz
3. cd libdes
4. make gcc
5. sudo make install

Now, you’ll find that the file libdes.a is now in /usr/local/lib.
Second, compile and install SMBProxy. Now here there were a couple of compilation errors that I had to deal with.
Here’s the diff output for crypto.c

trance@z0n3:~/Desktop$ diff smbproxy/crypto.c smbproxy-orig-src/crypto.c
40,41c40
< #include
< #define MD4_SIGNATURE_SIZE 16 --- >
46c45
<> static u_char Get7Bits(UCHAR *input, int startBit) {
58c57
<> static void MakeKey(UCHAR *key, UCHAR *des_key) {
74c73
<> void DesEncrypt(UCHAR *clear, UCHAR *key, UCHAR *cipher) {
85c84
<> void mkResponse(UCHAR **ntlmhash, UCHAR hash[MD4_SIGNATURE_SIZE], UCHAR* challenge) {
88c87
<> UCHAR ntlm_response[24];

Having done this there were still a few issues with the make comand.
The Makefile can be generated by running the following command:

trance@z0n3:~/Desktop/smbproxy-orig-src$ ./configure

Here’s the diff output of the Makefile:

trance@z0n3:~/Desktop$ diff smbproxy/Makefile smbproxy-orig-src/Makefile
10,11c10,11
< smbbf_include =" -Iinclude">
< libs ="">
—
> SMBBF_INCLUDE = -Iinclude
> LIBS = des
31c31
< $(LIBDES) $(LIBS)
—
> $(LIBDES)

The following libraries are required: openssl, openssl-dev, libdes for successfully compiling SMBProxy.

apt-get install openssl openssl-dev

I finally got the Certified Expert Penetration Tester (CEPT) with a good score on the practical. There were two parts to the certification : an objective multiple choice written test and a practical. To qualify one needs 70% on the written and 70% on the practical portion of the test.
The written test was not too challenging if you follow the material taught at the InfoSec Institute’s Advanced Ethical Hacking course, however, the practical made up on the lack of challenge. The practical involved writing an unpublished stack overflow exploit for a real-world commercial software of IACRB’s choosing, a format string exploit for a custom application and writing a patch for windows binary to subvert registration mechanism on the binary. One could write the exploit in the form of a python script (that I chose), a shell script , a perl script or a binary written in a language of our choosing. The solution could be quite flexible when it came to the choice of language for writing the exploits.
Personally speaking, this was a great learning experience for me and I plan to continue learning in the interesting field of vulnerability development!

I was playing with PaiMei and trying to get some initial stuff working on Pai Mei Reverse Engineering framework by Pedram Amini.
It was a smooth ride until the following steps:
1. Install MySQL
2. Install wxPython
3. Install GDE and uDraw

There was a slight problem in the __install_requirements.py file that it would always look at C:\Program Files for the files whereas my files were in S:\Program Files.
Either way a small change from C to S in the __install_requirements.py did the trick. Thereafter, when I ran __setup_mysql.py script I got the following error:

Seems like MySQL should not be running in “strict” mode while you run this script. I got this information from the following link:
http://paimei.openrce.org:8000/ticket/5

I recently got a Sansa e260 4 GB MP3 player just for kicks to check it out. Seems like the hardware runs a stripped down Windows install having FAT32 file system on it. What was interesting was, that somehow my files got corrupted and had to format the drive (My Computer -> eSansa(G:) -> Right click to “Format..”). All the folders disappeared and when I restarted they reappeared. What seemed to crash it was the presence of a few folders that I created not realizing that Sansa did not support folders as the HelpDesk person told me. Makes me wonder what kind of unstable condition would a folder creation have caused. I think I’ll need to further research this error.

I recently started blogging for InfoSec Pals. It was started by Palan Annamalai who was my colleague at Ernst & Young’s Advanced Security Center where I worked for a year and a half. Other people who are active bloggers on the site apart from Palan and I are : Sri Vasudevan, Jay Kelath and Felipe Moreno. Let’s see if I can maintain the technical content of both the blogs and keep the goodies coming.