Oh look, I still have a blog!

Hello Readers!,
I know its been awhile but thanks for not sending any threats or rotten fruit. Things have been very busy around g-c with work flooding back in and the new book, which is very behind. This no reason not to try to keep up with all of you and our new research.

I'll follow up with a new blog post tomorrow, a simple short one about what many forgot about basic CD/DVD forensics. Until then, did you know I'm google+ and twitter?

http://twitter.com/#!/HECFBlog
https://plus.google.com/u/0/?tab=wX#104808728995007755708/posts

Feel free to add me/follow me/circle me while I attempt to get back into the swing of things, so many new things for us to talk about in this one way conversation.

Speaking of two way conversations, I've put into speak at CEIC again and I'm looking for other conferences. Let me know if yours is looking for one!

CEIC 2011

Hello Readers,
Thanks to everyone who came to my session at CEIC 2011, I hope you enjoyed it. Here are my slides: link that I used in my presentation. I'll have the code up soon for everyone to download. I'll be making one post per exchange version so I can explain the procedures.

NCCDC is coming - My favorite time of year

Once a year the fine folks at the National Collegiate Cyber Defense Competition invite a team of people to participate in their event as red or white team members. I'm happy to announce that I've been asked to return as captain of the red team this year again on April 8-10 in San Antonio, Texas. I got my start as a professional in network security and though I speak about computer forensics publicly we at G-C still do network security for select clients.

For those not familiar with CCDC it is a national competition that pits teams of college contestants who have to defend their network while continuing to deploy new business services against a team of people who are looking to ruin their day.While there is always a team who wins the national title I've always felt that it's the red team who always wins since we have the most fun.

Getting involved with CCDC is something I've always enjoyed doing and would recommend others do as well, if you are looking to volunteer as either a good guy or a bad guy you should go here http://www.nationalccdc.org/index.php?option=com_content&view=article&id=58&Itemid=70 to get involved at either the national or local levels.


If you are company looking to recruit the best talent emerging out of today's universities you could also benefit by sponsoring, as we have, the event and get access to these students before they can write their own ticket. To sponsor go here:  http://www.nationalccdc.org/index.php?option=com_content&view=article&id=59&Itemid=37

New year, New book!

Hello Readers,
                       I thought I'd take this weeks post to announce that I just signed the contract with McGraw Hill to write a new book. It will be called 'Computer Forensics, A Beginner's Guide'. It's meant for those of you already in the IT field who are looking for a jump start into your first computer forensics investigations. I'll post more details as I finish the manuscript but we are currently set to have in stores in early November.

Oh no, it's GroupWise!

Hi there Reader,

For many years when I talked to a client about their network environment, these would be my words 'Oh no, it's GroupWise!' but not anymore!

Read more »

What are you missing? AIX

Happy February Readers,

I didn't want to miss last week's posting, but I also didn't have the time to make a quality post before leaving on a trip. So quality over quantity will hopefully gain favor with you. I'm taking a break in the What was wiped series to give myself some more time to gather what I need and instead I am continuing the What are you missing series in this post.

Doing forensics on specialized servers, which I will define as anything non wintel and whose file systems have no parsers supported in forensic tools, is an interesting challenge. You have to:

1. Research where the system log files exist

2. Determine what format the logs are in

3. Capture the metadata of the file system

4. Determine if the file system can be parsed by anything but the running OS

5. Determine if it's feasible to image the server via DD

6. Determine if here is any hardware specific evidence that exists

A good example of this would be an older AIX system as detailed below

Read more »

What was wiped? Part 1

Hello again Reader,

I've actually put an appointment on my calendar now to remind me to blog, let's see if reminders will ensure regular posts.This is a short beginning for part 1 to insure I meet these weekly updates.

Many times when you are working an investigation the question of spoliation will come up. In the most obvious scenarios of spoliation a suspect will use a tool that will to some extent wipe out his tracks. These tools come in three flavors:

1. Whole disk wipers: It's fairly obvious when this happens, though some suspects may tell you it's just encrypted. If they say that ask them what program they used to encrypt it and to please hand over the key.

2. File/directory wipers: If someone were to run a program such as bcwipe or eraser to delete files or directories the first thing these programs do is rename the file to prevent you from recovering what file was deleted. So if your suspect wiped 1,000 files you would find 1,000 randomly named files all seeming modified within seconds of each other on the disk from a different date. After renaming the file, it sets the time and after overwriting the contents of the file it sets the size to 0.

Here is a ftk imager view of a directory named temp with some random new files made:

Here is the same directory in ftk imager a second after wiping:

"How long these file stick around seems to vary by the file system. In older cases I found them months after the fact but on my Windows 7 system that I'm running ftk imager doing a view of my local physical drive some random files disappear in a couple seconds, which accounts for why we don't see 7 random files. " *This isn't exactly true, please see the update below* This wipe was done using bcwipe, the behavior of what wipers leave behind and how it runs on each OS and file system sounds like a good post for me to work on.

In part 2 we will go into system cleaners like CCleaner and some research into what they leave behind.

Update:

Looks like my disappearing wiped files are not a product of a different version of windows or the file system, it was the windows write cache. I made a couple of new files before and just wiped them immediately after, looks like they didn't actually get committed to the disk before I wiped them and thus would not be around afterwords.

To test this I downloaded a random set of source code from sourceforge, extracted it to a directory and then rebooted to make sure everything was flushed.

After rebooting I wiped seven files from a directory in the source tree and got seven wiped entries as expected:

As you can see, seven randomly named files all again with the date of 4/30/1986 and the time 11:43am. I guess this goes back to my last post, if something seems wrong double check your assumptions.

When I wipe the entire directory tree it then appears as an orphaned directory with all of the directory names and file names changed again to random letters with the same date as we saw before, except for the directories which remain the correct date (these times are in UTC so the date appears as 1/20/11):