Wednesday, September 18, 2013

Hello little NAS why are you trying to talk to Russia?

In a recent post I talked about securing your home network, so of course I want to make sure I practice what I preach.  My main server recently suffered some hardware failure, there was nothing critical on it so I am in no hurry to get it back up and running.  I took the opportunity to find something more dedicated to run the file sharing on the network so I picked up a QNAP  TS series device.  I figured yeah, this should do what I need.  Well I didn't realize that was able to replace most of the services that my bulky Dell server was hosting.  After getting it up and running I found it to have a slew of useful services like VPN, media server (DLNA) services, and of course file storage/sharing.  So I got the thing running, connected up the big USB HDD and restored all the shared paths and such.  Eventually I got the VPN working and made sure managing it was only done through SSL.

So I had it going for a couple weeks without any issues, until the morning I decided to check out my network traffic.  I saw some odd stuff in my firewall logs that didn't make sense, and they were coming from the QNAP system.  It started because I saw a good deal of inbound UDP traffic being blocked.  UDP is basically TCP's bastard cousin.  It is not typical for legitimate internet services to use UDP.  So I checked out some IP addresses and they were coming from the usual oversees locations.  No big thing, most likely internet scanning on UDP to see if anyone's firewall will allow it through.  So I continue through the log and notice outbound UDP traffic.  I panic a little and then notice it is going out over 6881.  Now my lovely firewall allows me to do an on-demand packet capture, which is handy as it sits between my LAN and Internet, so it can see everything.  So I ran the capture and then filtered the results in Wireshark:
Notice the many different non-US destinations?  Yeah that didn't sit right with me.  Did some digging as I have not memorized all my TCP/UDP port numbers and found that this is typical of BitTorrent listeners.  I did some additional searching and found that the QNAP has a Download Manager service that comes turned on by default.  This download manager runs like a Torrent listener so this is beacon traffic to the torrent network.  I took a look at some of the packets and found it to be random garbage, nothing malicious.  But still, that is traffic I don't want going out without my permission, least of all to overseas locations.  I made some changes on the firewall that would automatically block traffic based on country of origin and found a nifty forum post about disabling the feature and hardening the device further.

  • Disable Download Station - unless you can find a good use for it.  This can be done from "My Apps." Just slide the bar to the left.
  • Now we need some clean-up.  We will need to make sure only authorized networks can access the QNAP.  Go to the Security Settings in the QNAP control panel.

  • In the Security Settings, you will want to select "Allow connections from the list only."  Then add the internal IP address/ranges you wish to allow to access the device.  This is handy if you happen to have a guest wireless network that may touch your main network.  Again who would have that, it is just silly.  Refer to the image below, IP addresses are obfuscated, but those would change based on the network anyway.  I did have to add my VPN IP Pool in as it is different from the internal LAN.
So that is it, piece of cake!  Once you make the changes it will restart the network services, so you may lose access to the shares for a minute or 2.  After I made those changes the traffic pretty much stopped.  I am still getting a bunch of inbound UDP getting blocked but that should decline as well.  Anyway hope this is helpful to some folks.  The device is pretty useful but again, don't always trust the default settings or apps.  Take the time to understand what you plugged into your network!  Any questions feel free to leave a comment below!

So quick update on the network security... as I sit here waiting for my plane to Louisville for DerbyCon 2013, I decided to test my VPN to the home office.  It wouldn't connect, so through other magical means I remoted in a different way to check the systems.  Firewall check!  It was passing traffic nicely.  So logged into the QNAP where the service is hosted and immediately saw the warning indicator for unauthorized network attempting to connect on my VPN port.  Nifty, that made fixing the issue pretty easy.  Made the necessary changes and all is working now.  So if you lock your QNAP down and use the VPN service, you may need to open some ranges or just not use the block networks piece.  The VPN is only temporary until I can bring up a new full time server.

Sunday, September 15, 2013

Securing Your Home Network

Every now and again I try to take some time out of my weekend mornings to take a look at my network traffic.  I should certainly do it more often or enable some form of weekly report to be sent to me, maybe that will be a winter project this year.  In any event, with all the new tech we add to our home networks every year, it makes more sense to know just what exactly is going on in the network.  Big enterprises have numerous tools (not so much personnel) to monitor both outbound/inbound traffic, unfortunately the typical home user does not.  In fact many believe that if they slap in their Linksys/Netgear home router, they are good to go and everything will behave.  But with stories such as the "hacked" baby monitor in Texas, we know this is not true.  Just some corrections to that story, it wasn't an actual baby monitor, you know the two way radio sort of monitors.  It was a Foscam IP Video Camera, most likely of the wireless sort.  It sounded like the father took the appropriate steps in configuring it, but again, just doing what the manual tells you to, does not make it securely configured.

But I digress, the point of today's post is to help educate my not so tech savvy readers and make them aware that many of these consumer brand companies really don't put too much effort in securing their product.  They have some basics covered like changing the default password or enabling secure wireless, but something such as allowing access to the device over the internet, well that opens a door and invites trouble into your network.  Researchers and the bad guys are constantly scanning the internet for open ports to determine services that might be running on those ports.  You have your typical ones such as web based TCP 80 (http) and 443 (https), as well as email (SMTP/TCP25), FTP (TCP21), and SSH/SFTP (TCP22).  There are also standard services running on non standard ports; for example, http running TCP 8080.  This is typically done to either obscure a web server from the untrained script kiddie or run more than one web server from a single host.  In my case it would be to get web traffic through my cable companies routing rules, as residential internet typically filters popular traffic such as SMTP and HTTP on standard ports.  We can go into details another time on that.  With tools such as Shodan (See previous post) being used much more frequently and internet scanning software becoming more efficient (Check out the post from Robert Graham), it is getting much easier to find out what is running on people's networks.

So what does all this mean?  Well as consumers we need to start getting smart about what we are connecting to our home networks.  In the past the average home probably had 1-2 computers and possibly both wired and wireless networking.  Now a majority of homes have any number of smart phones, tablets, game consoles, laptops, and (maybe) a desktop all connected up.  They may also include network printers, Smart TVs, Smart Blu-ray players, and other media devices such as Apple TV or Roku.  All of these are now nodes on your home network and they all require internet access to function.  

Now of course we have all created a network diagram that we keep handy for reference... right?? Anyone?  Anyone besides the crickets?  OK I'm joking, only folks like myself who do this for a living will probably go the extra length and document the home network.  At least I can rest easy knowing that if I am ever hit by a truck, my wife will know what device to unplug to reset the cable modem.  I only partially joke about this, but it is not a bad idea to know what is connected to your home network, just draw it out on paper or make a simple list.  You don't need to make high end enterprise architecture diagrams, I mean that would be silly!  The first part to securing something is knowing what it consists of.  You know how many doors and windows you have in your home right?  Well think of your network in a similar way.  The less devices you expose to the internet, the better.  Exposed meaning you allow inbound access to them.  If you absolutely must have access to something while you are away from your home, then look into setting up a VPN.  It is not all that hard and there are a number of both hosted and local solutions out there.  I will be doing a write up on one such device coming up.  The VPN allows you to make a secure connection to your home network from outside.  The tunnel is encrypted so it is difficult to play a man-in-the-middle on.  Is it full proof?  absolutely not, but it is another layer to make it so the novice cannot get in.  In security we like to say, if someone wants something bad enough, they will get it, it is just a matter of time.  You best defense is to make it as hard as possible for them to do it. Think about it this way, putting frosted glass on windows, using thick curtains, and even placing warning signs on your property for dogs or an alarm system.  Granted these may throw up flags that you have valuable stuff, but it will keep the curious passer-bys from snooping around.  A determined criminal may risk it and smash in a window still but he may not be willing to tangle with a big dog.  

So this one went on log enough, I will end with this... don't assume the product manufacturers have your back, they want to make money and adding extra steps to secure something may take from their bottom line.  So go out and do some research on that next new gadget you want to add.  Know that you may need to do some extra work to harden it!  If you ever want more education on the matter, swing by your local Hackerspace, there are always folks willing to educate people on these sorts of things.  If you are local to CT, you can come by  We are usually around in the evenings during the week and random times on the weekends.  The weekly schedule is posted on Sundays.

Tuesday, September 3, 2013

Edumacation and Training: Who's responsible? You or your employer?

If you consciously decide to take a career in information technology, then you should have realized that school and training doesn't stop after you receive your degree.  The same goes for you if you decide to move into an information security position.  This realm is constantly evolving and you need to be willing to evolve with it, or find a new career.

Your goals may not align with your employer's...

If you are lucky enough to land a job with a company that will pay for training, then take advantage of it.  Just be ready to accept that what they are willing to train you on may not be in line with your personal career goals.  For example, if you work for a consulting company, they may want you certified with their primary vendors' products.  If it is a Microsoft Gold partner shop, then they need to maintain a certain number of MCSE/MCSA certified individuals to keep that partnership.  If you sell Cisco or Juniper products, the company may need those certificates as well.  They may not want to send you to SANS or Blackhat for training on the latest security topics.  Unless, of course, they are a security consulting company and they would rather your pen testing skills be honed.  If you are in a large enterprise, the training may be more open, as long as it fits in with your development plan, then it can be justified.  In any event take whatever training you can get, it will never be wasted and you might learn something interesting.

It may not be in the budget....

Be ready to hear that if you want an employer to pick up the bill for a conference.  Although it may benefit them that you receive some cutting edge knowledge, they may prefer you attend online webinars or local events, rather than sending you to San Francisco for RSA or Vegas for DEFCON and Blackhat.  If that is the case, don't be afraid to spend some of your own cash and use your personal time to hit up some of the smaller cons like DerbyCon (Louisville), ShmooCon (Washington D.C.), Thotcon (Chicago), and of course any of the many Security BSides events happening all over the world.  Most of these are pretty affordable, and all you need to do is come up with the means to get there.  If you can't afford a room, there is usually someone willing to split one.

Don't pass up excellent networking opportunities...

Back to the topic of the conferences, not only do you get exposed to some excellent talks, but these are also great opportunities to meet some interesting people.  Again, your goals may not align with your company's, but that doesn't mean you should ignore them.  Invest in yourself a little and get out to these cons.  Who knows, you might have a conversation with someone who may want you to come out the next year and speak at the con.  If it is a vendor, they may even pay for it.  Also, when at the conference, don't worry about getting to every talk on the schedule.  Take the time to participate in the "HallwayCon", grab coffee with some attendees, and don't be afraid to join a public dinner invite.  You never know who you will meet out there, they could lead you to the next stage of your career.

"I'm going as long as work approves..."

So something along those lines was said to me when talking about a BSides event that was in the next state.  They person was hoping work would pay for the single night at the hotel.  Since BSides are relatively cheap, and usually in driving distance, I will cough up the 100-200 bucks for a single night at the hotel.  Again, back to the networking opportunities and the education factor of these events, it is worth spending some of your own cash for it.  In some cases, you can claim these trips as a business expense, but check with your tax guy first.


Ultimately you are responsible for your own training and education.  If you want to succeed in your career, you will make it happen.  Whether you get work to pay for it, or not, you should still do it.  If work wants to get you trained on something not necessarily related to your goals, take it!  It is knowledge you did not have before.  So good luck out there and keep up the learning!  Maybe we will bump into each other at the next HallwayCon.  Otherwise see you at DerbyCon 2013 in Louisville this year!