Author Archives: Chris J

About Chris J

Chris J studies physical and information security. He started the Ann Arbor Chapter of TOOOL, attended Eastern Michigan University got a degree in Applied Information Assurance. Work involves Threat Intelligence.

More Fail2Ban fun with Debian Stretch

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Yesterday, going through email yesterday, mostly logcheck emails, I found that Apache wasn’t blocking the attackers. It was seeing them, but not adding the ip address to iptables block list.

The fix was setting up the maxretry it was set rather high, I moved it down to 1 like I had it in the past. I also adjusted the search time to 1 hour and the ban time to 7 days. I thought I was good, and didn’t give it a second thought.

Today, looking at the logcheck emails (really it’s a great IDS for system admins to get a view into their box), there are a lot of automated attacks on the mail server NOT BEING BLOCKED!!! It worked yesterday, there were even banned ip addresses in the chain.

After lots of digging, and several changes that didn’t work, I decided to go for the bad option.

Really the real reason was that Fail2Ban had been around for a while. Things changed, and I had a weird mishmash of configuration files. After the install I removed the files in the package that were not debian related, not sure why bsd; osx; or fedora are in the Debian package to start with.

Followed the local customization file directions creating jail.d/server-defaults.conf with apache-auth and dovecot in them. ssh is handled by defaults-debian.conf. Why the new file, in case the Debian one gets over-written by new stuff later.

Restart the service and…

Still not working for dovecot.!? (tailing the log and watching iptables).

Turns out, it’s where Fail2Ban was set for default to watch for login errors for Dovecot (also noted through the logs). It’s looking in /var/log/mail.warn. I don’t know if I changed it, or it’s legacy left over, or what, but my box it’s /var/log/auth.log where Dovecot login failures go. So I added the logpath to jail.d/server-defaults.conf, restarted Fail2Ban and it worked.

Fail2Ban problems with Debian Stretch

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This week The Debian project released “Jessie” (Debian 8.0) as stable. I like to keep my servers a little more ahead of the curve than that, so I upgraded to the new testing branch “Stretch”.

While going through my logs from yesterday and this morning, log checker is awesome, I saw someone hitting my mail server. Normally you only get 1 chance to log in as a non-existent account before Fail2ban kicks in and adds the ip address to my Netfilter iptables jail. This address kept showing up, hour after hour in the logs, and multiple user names.

Looking, I found out that while running, it wasn’t catching all the rules for Fail2ban. I checked the configuration files, and things checked out OK. So I fell back on the old restart the service and see what errors pop.

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Home Lab – Lines to the basement

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I currently have 2 lines ran to the basement. One black 15 foot, 1 red 25 foot. I ran the black line last year before the basement flooded in August, but I couldn’t tel you why I did it now. I really don’t remember. I think it was for my old tower. The red line is for the span port. I chose to color code them to make it easier to know what does what.

I used the pre-drilled holes in the floor for some reason the cable provider for who lived here before me drilled 2 holes next to each other. The old cable is still there, the other was empty, and what my provide used. Dropping the black line was quick and easy. The red cable though, was a pain in the butt. I could get it in the hole, but it would get stuck at the bottom edge of the wood. I ended up pulling up a length of coax, and then taping the span cable to it. I then fed it through the hole. That got it down there, then I fed from above instead of pulled because it was a tight fit, and figured pushing would do less damage to the cat5e twisted pairs.

I was thinking it would have been great to have flight line, fish tape, or a pole, but after looking at the head on a fish tape last night, I don’t think that would have worked either.

color code:
Black – switch to switch
white – entertainment
red – span
blue – Firewall to Switch, Switch to Router
green – ISP

I don’t know what color I’m going to use for the PI farm. I was thinking maybe purple.

Home Lab – Changes

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I’ve made changes to the layout of my home lab. This is the current plan, because I can’t afford the Cisco switch I want right now. I also don’t think it’s worth getting a second line to the house, since I plan on moving by October.

The new design is to have my home network and the lab network mixed. I do have one more wireless router I could put in place to isolate the lab, but not going to for right now. If I need to limit things for something, I can always change. It’s also split between 2 floors, which is why there are 2 switches.

Lab Design v2

 

 

 

 

 

 

 

The Single Board Farm is 6 Raspberry Pi B, 4 Raspberry Pi B+, 2 Raspberry Pi 2, and once I can get them, Odroid C1 (probably 2).

Book Review: Meditation for Warriors

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I’ve been studying Martial Arts for around 30 years on. I’ve gotten a couple of other books by Loren W. Christensen, mostly on training and diet. However Meditation For Warriors: Practical Mediation for Cops, Solders, and Martial  Artists is the first one that focused on the mental aspect.

This book is written as a practical guide to focus your mind, giving you a calmer demeanor, and allows you to stay cool, calm, and collected when the stuff hits the fan.

I really like that while it’s geared towards “Warriors” (Police, Soldiers, Martial Artists), it’s a really down to earth book that anyone could read and get a better understanding of meditation. Part of the goal of the book was to give non-practitioners a real world view of the importance of meditation.

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Book Review: Personal Digital Securty

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I read Personal Digital Security: Protecting Yourself From Online Crime (Amazon affiliate link) by Michael Bazzell. I think this book is a good place to start, if someone wants to learn more about computer security.  A seasoned practitioner of Information Security could use this book as a core component to create a great Security Awareness Training program for users.

Mr. Bazzell starts off as if the reader knows very little information on computer security. However by the end of the book, he’s very conversational in tone, and is suggesting the reader shares what he learned.

The book has a building block approach. Not all readers will need to go chapter by chapter. But starting with Chapters 1 and 2, Mr. Bazzell starts a great foundation for the things in the rest of the book. The book starts with protecting your computer, and then your passwords. From there he goes on to show how to protect your online accounts, your data, and your credit cards, your debit and your banking information. Next is about protecting your telephones, cellular and work. Chapters 8 and 9 go in to always connected devices and wireless networking. Chapter 10 talks about how parents can protect their children online.

If your bank accounts  or credit card has been compromised and you want a deeper understanding read this book. If you want to create a Security Awareness Program, start with this book. If you want to get in to Computer Security, this book covers the basics you should already know by the time you walk in to a class room or entry level job.

* Update 2024-10-01: changed to Amazon Affiliate Link, which I earn a commission from qualifying purchases.

 

Unofficial training at Circle City Con

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I’ll be presenting at Circle City Con this year, on Wireless Intrusion Detection with the Raspberry Pi. I’ve done  some test runs of the talk, and have ended with people wanting to contact me later if they have questions. Mainly if they get stuck. Also one of the comments from the reviewers when I submitted my talk was this would be better as a training class.

After talking to one of the organizers, here is how this is going to work. Currently I’m scheduled to talk on Saturday. After my talk, through the end of the Conference I can be available (as long as I’m not in a training sessions) to use some of the the common / lobby area to work with people wanting to set up the wireless drones, what kismet calls sensors.

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home lab – more pfsense work

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Finally got time to pick up from where I left off last time. I’ve had a hard time getting to do lab work. Anyway. I connected my pfSense box to my AT&T U-verse Router Gateway, something I’ve been worried about, and it worked. I was worried because in the past, it would shut down the RG saying there was a network behind network, turn on DMZ Plus mode, and everything would be broken.

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home lab – firewall installing pfSesne

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There are lots of good howtos out there to get the system installed. I followed this one, since it was for the same hardware: Build an awesome APU based pfSense Router.

Issues were with the installer software. It took a few tries to figure out I needed to run it as admin, mostly because the screens are all in German (I think). I tried other software (the one I use for the Raspberry Pi stuff) didn’t work.

Booted off the console, used the installer (after I got the right image, can’t use the iso image), and installed it. Next up, getting it on a network to use the Web interface to configure the box. Or use SSH. Maybe just plug in the laptop and see what happens. That’s half the fun anyway, or so I think.

Home Lab – Firewall PC Engine APU1D4 DYI Build

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Got the first firewall for the lab. It is a PC Engine APU1D4 D.Y.I Kit from Netgate. This hardware has been going out of stock constantly. I got the 30 gig flash drive from Amazon, for less. I should have taken pictures as I was building it, but was just excited to be building it.

The good:

  • easy open packaging
  • other than the heat spreader it went together really quickly
  • Online documentation available

The bad:

  • No Instructions in the box
  • The heat spreaders didn’t like to stay on the chips
  • the heat sink move pulling the spreader off with it while putting the bottom on. Didn’t cause problems, but had to stop and reline up the head spreader to the chips (stuck to heat sink).

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