Thursday, April 17, 2014

Letter to Management

This letter was posted today....and it could have been sent to our management.  (It's not.)  Many of the points echo exactly what is happening here.  I would say, the biggest excuse I hear is that management does not want to disrupt the corporate culture in implementing security controls.

I fear that a breach or severe incident will be the catalyst for change and implementing controls.  Yes, I've had many small wins, but there is lots to do.

Wednesday, April 16, 2014

humans.txt Appearing in our Firewall Logs

This morning I came in to work figuring I would continue working on analysis of our infrastructure for the Heartbleed bug.  We seem to be fine...this is a case where fortunately, we get lucky because we have been using such an old version of OpenSSL.  Which means we're probably vulnerable to a whole host of other vulnerabilities.  But, we appear to be not vulnerable to Heartbleed.  Which is a good thing.

Early, a co-worker came to me asking if I had seen the note from our DDoS mitigation provider.  It was the first such email to provide a source address for the attack.  The "attack" only lasted four minutes, and to me, was not much to worry about.  However, there was at least an indicator to look for in the logs.  I popped the source address into our firewall logs, and was presented 134 records back; all targeting various servers of ours. 

And here was the unique finding.  Every request string looked something like:
http://ourserver/some_bogus_directory/some_bogus_file.php?php121dir=http://www.google.com/humans.txt
I fully admit, I had never heard of a humans.txt file; I knew about robots.txt, but not humans.txt.  So I looked it up.  We don't use it.  Next, I fetched Google's human.txt file to see what was in there.  Nothing untoward.

The best I can come up with is that this is some kind of remote file inclusion attack and the attacker is looking for vulnerable php servers.

I found a great site that had a little more info here, but their mitigation was in using .htaccess; we use our firewall.  I did not find much more information, so anyone that wants to shed a little more light on the subject, feel free to leave a comment.

Friday, March 28, 2014

Sophos Antivirus and EMET

In looking for mitigations for the recently announced Microsoft Word 0-day, I decided to install EMET on both my desktop and my laptop.  I fully admit, I'm not an EMET guru, nor do I know a lot about it.  I have found many directions for EMET (a good one here) so installation was a bit of a breeze.  However, tweaking it is another story.

First, Firefox 28 wouldn't start.  So, I had to tweak the application settings for Firefox to find out which particular protection was preventing it from starting up.  (Turns out, it was ROP.)

Then, upon turning EMET loose, I received two "Quarantine Announcements" from our Sophos Antivirus.  The notice was for a buffer overflow in IE and Acrobat reader.  From my analysis, the best I can tell is that Sophos saw EMET protecting those applications and didn't know how to report it.  I asked our Sophos administrator if he had heard anything about Sophos and EMET, but he didn't know what EMET was.  I authorized the activity in Sophos, and rebooted a couple of times to see if Sophos would report the activity each time I booted up.  So far, so good.

If I find out exactly how the buffer overflow was caught by Sophos, I'll update this post.

Monday, March 24, 2014

Python Links Updated

Just a quick note that I've updated my list of Learning Python resources after reading Harlan's great post.  My original (and now updated) post (and list) can be found here.

Thursday, March 20, 2014

Getting Started with Security Onion

After getting alerts from our DoS protection company that are vague, one of the network engineers and myself decided we needed to gain more visibility into the network.  We want to better understand these events and make a decision as to whether or not they are truly incidents.  Further, after we get notification of an event, we want to find the traffic to study it.  Enter Security Onion.  This tool is awesome, as we can run Snort, shoot the output to Snorby, and capture the data as well.  We're pretty sure that we have a box capable of running Security Onion, it's more a matter of how much data we want to keep.  Right now, we have a 1+ terabyte drive doing the heavy lifting.  We're just barely making it before the job to purge runs.

Our first shot at getting it up and running was fairly successful.  Data is flowing, we saw some alerts.  Next on the agenda was to start tuning it such that we are not drinking from the fire hose.

And, now we've broken Security Onion.  We're not sure where yet.  Events are coming in.  Our sensor NIC has packets traversing it.  However, there's nothing showing up in Snorby.  So, on to more trouble shooting.  Fortunately, this Security Onion server is not production-ready.  We knew going in that we would have much tuning before we could start truly relying on the output in a production environment.  The next step is to figure out what broke down and see what we can get back.

Wednesday, March 12, 2014

Finding hostnames on a Subnet

We have offices all over the world.  What I came to learn today is that there are two countries where we have very poor visibility into our own corporate networks.  To the point that I suspect that they are not managed very well, if at all.  I know I chase down malware in a couple of the networks on a daily basis. 

One of our admins asked me if there is a way that we can get all of the hostnames on one of those subnets that we don't have much visibility to.  NMAP would have worked well, but I wanted to come up with a command that I could have had a non-technical person run and send me the output. So, using a little Command Line Kung-Fu, I came up with:

for /L %A in (0 1 255) do nbtstat -A "XXX.XX.XXX.%A">>hosts.txt
Substitute your subnet for the Xs in that command.

It worked like a champ.  I suspect that there is an easier way to do this, but this worked easy enough.

Thursday, March 6, 2014

Hunting for Zeus Throughout the Network

I average finding a little more than one Zeus infection a day.  I know the reasons.  The root causes are there are some major security controls missing from the environment due to culture.  Adding those controls is a challenge and is a long-term strategy.  We are in the infancy of a Security Awareness campaign that is just starting to teach people the dangers of clicking on links in Spam or falling for phishing.  Occasionally, the FireEye sensor would alert to someone clicking a Zeus link.  I suspect more click the links than I am aware.

Using the Check Point's SmartLog, I've worked up a little query to help me spot some of the big outbreaks.  I grabbed the domains from the ZeusTracker, and built a mini-query (which I then pasted in the query bar.) 

dest:(domain or domain or domain or bizserviceszero.com or ....)
Periodically, I'll check the domains on ZeusTracker and run a diff to see what enters the list and what gets removed.  I know that there are better ways to do this, and I'd love to implement  some of those methods.  High on my list is adding a Snort box, or even SecurityOnion.

A small win for the day, but at least I can find these machines.  Hopefully, when I've built up some metrics, I can support changing the environment, and use the number of infections cleaned up as the driver.

Sunday, March 2, 2014

RSA Conference: Friday

I woke up on Friday to cloudy weather.  With an afternoon flight, I was on the fence with going to hear more talks.  I figured I would wait until after a shower.  Upon getting out of the shower, it was POURING out.  I'm glad California was getting the rain it needed, but...I didn't want to walk in it.  However, after getting dressed, it had stopped raining, and actually looked like it was lightening up. I decided to chance it for one more talk.  I probably could have gone to two...but there was no way I wanted it to be close at the airport.

The talk I went to was:
  • Operation Olympic Games is the Tom Clancy Spy Story that Changed Everything - by Rick Howard.  Wow, this was a great talk. I'm looking at my notes, and I see that I stopped somewhere after the first ten or fifteen minutes.  It was that good and engaging.  Rather than tell the technical story of Stuxnet, this talk discussed the history of the operations and the planning that went into it.  Further, Rick put forth some interesting theories that certainly have merit.
And with that I bid the conference goodbye. I fully admit that I wasn't sure what I would get out of it, and expectations were exceeded.  I've written the dates down for next year, and we'll see what happens.  As I write this, I'm starting to plan on how I'll use and implement some of the notes and ideas that were generated at the show.

Friday, February 28, 2014

RSA Conference 2014: Thursday

I woke up and it was absolutely pouring out, I thought it was going to be a repeat of yesterday.  Fortunately, by the time I started walking down the hill towards the Moscone Center, it had stopped raining.  And, while eating breakfast I noticed the sun coming out, a welcome addition.  Breakfast is served 7-8 in the morning.  The first conference I had scheduled was 9:20, but I thought to myself, I don't want to waste the time, so I decided on an 8:00 talk.  I'm glad I did.  Here's the talks I went to today:
  • Cloud Ninja: Catch Me If You Can - by Rob Ragan and Oscar Salazar.  Initially, I had this time slot open but at the last minute, I decided to pick a talk and go.  I'm glad I did.  This talk was awesome.  Initially, I thought it might be neat to hear a session with a little offense to it, seeing as how I mostly focus on defensive security.  But, as the talk focused on (ab)using free trials of company's software to build a botnet, I realized that there were dire implications for the company where I work.  This was a great talk that gave me information to go home and battle the developers.
  • Keeping Up with the Joneses: How Does Your Insider Threat Program Stack Up - by Dawn Cappelli and Randall Trzeciak.  Probably of all the talks I scheduled myself to see, this was number one.  I have their book, so it was great to hear Dawn and Randall talk.  Of course they backed up their research with plenty of numbers and examples.  They gave great advice on building and working an Insider Threat program.
  • The Future of Exploits, Developing Hidden C&C and Kittens by James Lyne. I picked this talk as I wanted to hear a talk by one of our company's vendors and I suspected it might get a little deep.  It didn't get too deep, and I'll tell you, I've never laughed so hard in a conference talk.  A great talk, kept light, with lots of great information.  And, now I've learned a great little story to explain buffer overflows.
I did not attend the Keynote talks today, instead I took a walk up to Fisherman's Wharf to see the Rock, seals, and a tour of the USS Pampanito.

I did attend the Codebreakers Bash, which was really well done.  They gave out these blinking LEDs, and now it is my hotel room has become a disco.  I'll have to cover it before going to sleep.

I fly out tomorrow, in the afternoon.  So, I'm on the fence with going to a talk tomorrow.  I'm tempted, to go see one more.  Probably the decision will be made by what time I get up. I will miss the keynotes tomorrow, and that means missing Stephen Colbert.  But I think I'll be ready to get on a plane.

Wednesday, February 26, 2014

RSA Conference 2014: Wednesday

In getting yesterday's post up, there are a couple of things I forgot to include: a couple of general thoughts on the conference.  First, there is usually twenty minutes (or more)  between sessions.  So far, I've found this to be ample time to get from one track to another...and that includes going between West and one of the other buildings, like North.  That even holds true for today, when it rained.  I noticed today that in all talks you can hear the jingling of the badge holders - it reminds me of the clacking of poker chips in a poker room - and ultimately, it's white noise.  Pro Tip:  If you are sitting in the front of a session, be careful with what you are surfing on your laptop.  Screens project more than you think.  Finally, one thing that irks me are the session attendees that have to take a picture of EVERY slide, with their IPAD.  Really?  In one talk yesterday, I noticed a presenter spotted someone doing that, and I got the feeling he varied his pace just to throw the person taking pictures off.

Today was another busy day.  Here are the talks I went to:
  • Hacking Exposed: Day of Destruction by the CrowdStrike guys, George Kurtz and Dmitri Alperovitch.  This was an awesome talk, where they literally destroyed some computers.  Yes, I think a couple were VMs, but they bricked at least one laptop.  And they showed how malware could literally fry a machine.  My question I didn't get to ask was:  could you do that on an airplane, or a hospital?  Consequences would be dire.
  • Gumshoes - Security Investigative Journalists Speak Out - Dan Hubbard from OpenDNS moderated a panel of Brian Krebs, Nicole Perlroth, and Kevin Poulsen. Again, this was another really great talk that I selected because I follow Brian Krebs' and Kevin Poulsen's blog religiously.  I hadn't heard of Nicole's work before, but I just added it to my feed reader.  Lots of great stuff was discussed.
  • Using Data Breadcrumbs to ID Targeted Attacks - Dan Hubbard.  This was only a twenty minute talk, and I enjoyed it.  It gave me some ideas to take back to the mother ship.
In the afternoon I went to the keynote talks.  Already, I look forward to tomorrow's talks.