I planned on doing a few blog posts in December but due to a few great December surprises I wasn’t online much. My month started off by taking a much needed relaxing week of vacation in San Diego with my wife. On the last day of our trip I got the type of email everyone hopes for: “I know this is last minute, but would you like to go to the SANS CDI conference in DC next week?”.
CDI was my first east coast SANS conference and it was well worth the trip. I got to spend a lot of time with some absolutely amazing people and it was truly one of the best weeks of my life. I’m not sure yet what conferences I’ll be going to in 2015 but I can’t wait to find out.
It was a great end to a fantastic year. I got the opportunity to attend several SANS trainings in person as well as online. Got a chance to attend some other penetration testing training. Got to attend my first Blackhat and Defcon thanks to the generosity of Don over at ethicalhacker.net and made some great friends with similar interests to mine.
I improved my knowledge and skills dramatically in 2014 but still have a lot of work to do in some areas including exploit development and reverse engineering. I’m also starting to play with things like using binwalk to analyze firmware and I just got a Riff Box to try to learn to JTAG mobile devices.
Thank you so much to everyone I’ve interacted with this year and hopefully 2015 will be even better.
Recently on the SANS DFIR mailing list one of the members announced he had put together a Network Forensics challenge for anyone who wanted to participate. The challenge is at http://blog.mywarwithentropy.com/2014/11/spy-hunter-holiday-challenge-2014.html where you can download a large pcap and a PDF with instructions.
I’ve only had a small amount of time to play with the pcap but it’s very well done and I’m looking forward to digging deeper into it.
Congratulations to James Lieu for winning the paperback copy of “Hacking Exposed 7: Network Security Secrets & Solutions“.
Last week I attended the SANS SEC575 Mobile Device Security and Ethical Hacking course at Network Security 2014 in Las Vegas. It was an enjoyable class and I just finished the first draft of my index (the book for day #3 is close to 300 pages!). I plan on writing up a review of the course in the next few days.
In addition to the class I was able to spend time with some great people and participate in both nights of Core Netwars. Netwars would be fun no matter what but it was made even better by sitting with friendly and knowledgeable people. I ended up getting about half a dozen questions into level 3 and finished 14th on the alumni scoreboard. While I always feel like I could have done better Netwars is a great way to see the progress that I’ve made from year to year and I felt a lot more comfortable than I have in previous years.
Congratulations to book giveaway #1 winner Matt Williams (@mattwilliams31) who won a paperback copy of Richard Bejtlich’s “The Practice of Network Security Monitoring: Understanding Incident Detection and Response“.
Book Giveaway #2 is for a paperback copy of “Hacking Exposed 7: Network Security Secrets & Solutions“.
Once again I’m limiting the book giveaways to U.S. residents only to keep the shipping costs down but I will do a giveaway later this year that will be open to everyone.
The drawing is open until 10/26/2014 so good luck!
a Rafflecopter giveaway
Earlier this year I wrote an extremely short post discussing the Red Team Field Manual (RTFM) book. I’m currently on my third copy of the book (I’ve given the first two away) and I have a copy in my backpack at all times. I recently saw some traffic on a SANS mailing list about similar book geared towards blue teamers and had to check it out.
Like the RTFM, “Blue Team Handbook: Incident Response Edition” is small, affordable and is more of a collection of steps and command examples than a traditional book meant to be read from start to finish. The Blue Team Handbook covers topics such as Windows and Linux volatile data system investigation, network traffic analysis techniques, suspicious network traffic patterns and Snort configuration and usage. Amazon now lists an updated version 2.0 of the book with 20 new pages including information on database incident response.
The book is currently listed for under $14 on amazon and is perfect to keep with the RTFM in my backpack. If having a printed collection of incident response methodology and commands is something you’d like to have the Blue Team Handbook is worth checking out. When I inevitably give my current copy away I’ll have an excuse to get the new version with the database coverage 🙂
My “A First-Timer’s Experience at Black Hat and DEFCON” article I talked about in my last post is now live on the front page of ethicalhacker.net along with a picture of Kevin Mitnick and I. When the article went live earlier this week I couldn’t help inserting a mental caption of “A hacker & a hack” when I saw the picture 🙂
Even though it wasn’t a technical article I’m still quite honored to have an article on the front page of ethicalhacker.net and it’s a nice reminder of the progress I’ve made over the past two and a half years. To spread around a little of the good fortune I’m going to give away some books that I already had copies of but got additional copies of at Blackhat.
I’m limiting the book giveaways to U.S. residents only to keep the shipping costs down but after all the book’s are given away I’ll think of a small giveaway that I’ll open up for everyone.
Giveaway #1 is for one paperback copy of “The Practice of Network Security Monitoring” by Richard Bejtlich. It’s a phenomenal book that I’m sure the winner will enjoy. I’ve set this giveaway up to run between 9/21 and 10/11 so good luck to all.
a Rafflecopter giveaway
In a serious contender for the “my favorite email of the year” award I was recently contacted by Don from ethicalhacker.net and asked if I was interested in a free briefings pass for Black Hat this year. I’ve never been to Black Hat or Defcon so I jumped at the chance.
I’ll be attending Black Hat and Defcon so if anyone has any tips for a first-timer please let me know. The only thing I’m sure of so far is that I’ll keep my Wi-Fi off the entire time 🙂
I haven’t had a ton of time to study recently but what time I have had I’ve used on C and assembly language. I went through a small book on C programming to get more familiar with the language and am currently watching SecurityTube’s “x86 Assembly Language and Shellcoding on Linux” course.
I’m halfway through the course and Vivek has done an outstanding job of explaining and demonstrating the concepts of assembly language in a way that has made it easy for me to learn. I’ll probably do a more in depth review after I’ve watched more videos but I can say that at $39 a month pentesteracademy.com is a great value for learning resources.
As I discussed in my previous post I recently started playing with GPU password cracking. After some modifications to my desktop system my machine was cracking passwords at a rate I was quite pleased with. After I put it through its paces on a few passwords I wondered how it would perform mining crypto-currency. I had zero experience in that area so I did some internet research to help me get started.
One of the first themes I started seeing was that if your main motivation for mining crypto-currency was profit than you should likely run away. The consensus was that if you were interested in crypto, alternative currencies or other similar topics then this maybe a nice hobby for you but if your main interest in crypto-currency was money then you would be better off spending your money buying them directly rather than mining them.
One of the next things I found out was that I was not going to be able to mine for Bitcoins using my new graphics card. When bitcoin mining was just starting people were using their computer’s CPUs for mining. The next step in the evolution was bitcoin mining using graphics cards. Just like with password cracking GPUs offer a huge speed advantaged compared to CPUs. Unfortunately for GPU miners there was one more evolution: the transition to application-specific integrated circuit, or ASICs. ASICs are specially made devices that can crack a specific algorithm at a much higher rate than a GPU and usually with much lower power consumption. The downside is that when the ASICs are no longer cost efficient to use for mining purposes they have none of the other uses that a video card has.
When I started doing research into this area I almost bought a Bitmain AntMiner S1 Asic which mines SHA256 (the algorithm used by Bitcoins) at a rate of 180 GHs which is FAR faster than even multiple GPUs can mine. When I crunched the numbers a month and a half ago the price was $240 and they would mine about $5 worth of bitcoin a day. I just checked at the price hasn’t come down but due to crypto currency’s getting harder to mine as they age (by design) the devices now mine about $3.20 worth of bitcoin each day. After you account for the cost of power it’s going to be a while before the cost is recouped.
While Bitcoin is by far the biggest of the crypto-currencies there are other currencies which are often referred to as “alt-coins”. Most of these coins use algorithms other than SHA256. Some of the most common are:
Scrypt (Used by popular alt-coins such as Litecoin and Dogecoin): Within the past two months Scrypt ASICs have been released which makes GPU mining for Scrypt based crypto-currencies inefficient.
N-Scrypt (Used by Vertcoin and a few other alt-coins): There are currently no ASICs for the N-Scrypt algorithm and the developers say that if any N-Scrypt ASICs are ever developed they will fork the algorithm to render them useless.
X-11, X-13 & X-15 (Used by a larger number of alt-coins including Darkcoin and Cryptocoin): X-11 and X-13 are very GPU friendly (low temperature and high efficiency) algorithms used by a larger number of recent alt-coins. As I type this a new algorithm (X-15) is just emerging.
Since I already had a good graphics card and wanted Bitcoins the logical choice seemed to be using my GPU to mine other crypto currencies and trade those for Bitcoins. With a full time job and other obligations I don’t have a lot of time to track trends, trade currencies etc. so my best option was to join a multi-pool where a large number of individuals work together to mine crypto-currencies which are automatically exchanged for bitcoins. I found exactly what I was looking for at trademybit.com. The owner of the pool charges .05% to mine there but the pool automatically switches between whatever currency offers the best effort/value ratio for your algorithm of choice. For an extra 2% the pool will also automatically exchange all of the alt-coins you mine into bitcoins. I personally find the fees well worth the cost. The amount I earn every day can vary greatly and it’s definitely been slow lately but in the past month and a half I’ve earned around $40 worth of bitcoins. I’m not sure how much additional power I’m using by having the computer on when I otherwise wouldn’t but since I already had the equipment and I find the whole field interesting I’m more than happy with my results so far.
Last year I decided to buy a desktop computer to keep in my home office to run VMs and eventually set up to crack passwords. I didn’t want to spend too much but I was able to find a new dell XPS on eBay with an i7 processor, 16GB of ram and 2TB of hard drive space for $700. I had used john the ripper to crack password hashes quite a few times but hadn’t messed with using a GPU to crack passwords.
A few weeks ago I decided to finally get the machine setup to use the GPU to crack passwords. I knew that ATI graphics cards tended to perform better than NVIDA cards but I had hoped that since the machine was a XPS the NVIDA graphics card in it would at least do a passable job. As I started doing some research I quickly realized that the NVIDA GX 620 currently in the machine wasn’t going to be able to crack passwords at a rate anywhere near that found in higher end cards so an upgrade was in order.
I did a little bit of reading and the ATI 7950 ($230 with a $20 rebate at newegg.com) seemed like a good option for the price. Unfortunately I knew the card would be quite a bit larger and need more power than the stock card so a new case and power supply were in order as well. I ended up grabbing an Azza 9000 case and 600 watt Corsair power supply. The total cost for the graphics card, case and power supply were just under $500 and hopefully I get back the $50 in rebates I sent off.
When the video card arrived it was instantly obvious that I made the right call by getting the bigger case as the 7950 dwarfed the gx 620.
If I thought the video card was a big increase in size that was nothing compared to the monster that was the Azza 9000 case that arrived the next day. I wasn’t sure if that thing would fit through the door. I spent a few hours transferring the motherboard and installing all of the components into the new case but the process was relatively painless. When everything was said and done this is how it looked.
Once it was up and running I updated the video card drivers and installed the latest version of the password cracking program hashcat. I ran hashcat in benchmark mode to see what speeds I could expect for different password hash formats and was quite pleased with the results. AES and RIPEMD-160 TrueCrypt passwords were just under 78,000 guess a second and WPA/WPA2 handshake captures were cracked at a rate of 111,000 guesses a second. I tested a few different files and the real world results were very close to the listed benchmarks.
I’ll probably do a more in depth post on hashcat usage in the near future but right now I’m using the 15GB wordlist from crackstation (https://crackstation.net/buy-crackstation-wordlist-password-cracking-dictionary.htm). Hashcat also has some brute force and hybrid options.
If I had to do it all over again the only change I would make is getting a bigger power supply. The one I have now is perfect for the setup I have but if I ever decide to expand to a multi GPU motherboard in the future I’ll need more then 600 watts.
One unexpected side effect to this upgrade was that I backdoored myself into a new hobby. As soon as I was done testing the password cracking capabilities and the machine was sitting idle I wondered how it would perform mining crypto currencies. I’ve had a lot of fun researching the topic and trying different things and will probably write about that in my next post.
My box of books and swag for the 2014 SANS Cybercon showed up today so I’m pretty much like a kid on Christmas morning flipping through my new books. I signed up for the SEC 560 class (taught by Kevin Fiscus) and am looking forward to a great week.