Cloudflare and Dome9 Blacklister Scripts (Bash/Python)
One of my servers was under attack from an IP in China recently (some lame automated SQLi), but I figured I’d blackhole the source IP anyway.
My first step was to blacklist in Dome9, which I use to manage that server’s firewall, but after noticing that the attacks were still hitting my server I remembered that because I also use Cloudflare and those attacks were getting tunnelled through their network. So the solution (for that particular attack) was to also blacklist the source IP in Cloudflare. When another stupid attack came in a day or so later, I did the same and realised that it would be much easier if I automated the whole process.
So I threw together a Bash script (and then a Python script) that leverages the Cloudflare and Dome9 APIs to submit a given IP address to one or both services.
I’ve put these into my scripts repo on GitHub. Simply insert your Cloudflare and/or Dome9 API keys into the configuration portion of the script and go. Using this you could conceivably fully automate it by auto-detecting brute-force type attacks using a script on the server and calling this script to make the blacklist updates.
Bearing in mind these were very hastily put together, any feedback/improvements are welcome!
Dome9 Package for Synology NAS
I own a Synology DS413j NAS, and without wanting to write a whole review about it, these things are awesome, the management UI is great, and you can run all kinds of packages on them. One thing I like to do with mine is run an OpenVPN server so that I can VPN into home and do cool stuff.
But I was a bit concerned about the notion of having my NAS internet-facing, even if it was only OpenVPN’s UDP port. So, powering through with my love for all things Dome9 (I swear they don’t pay me), I wrote my own little package that installs the Dome9 Agent onto a Synology NAS and allows you to control its firewall (and make dynamic access requests) through the Dome9 service. Now I can make pretty much any of my NAS’ services available to the internet, and not have to worry about random attackers discovering those services. Similar to Single Packet Authorization (although easier to set up and use), Dome9 allows you to dynamically open one or more ports to a given IP for a period of time, and so while the port is available to you, the services remain completely invisible to everyone else.
This is the first release of the Dome9 package, and while it may need more work to support other VPN protocols, it’s ready for testing. If you do use this package, I’d be keen to hear from you, as I’ve yet to find another Synology-owning Dome9 user!
To install this package, simply download the dome9.spk file (below) and use the Manual Install option in the Package Center in DSM. You will need to have a Dome9 account and enter your pairing key to allow the agent to pair with the Dome9 service.
Honeyport Python Script with Local Firewall and Dome9 Support
Following on from my linux bash honeyport script (read this first if you don’t know what a Honeyport is), I wanted to write a script that works across platforms to accept connections on a given port and block that IP using the local firewall – IPFW on Mac OS X, iptables on Linux, or Windows Firewall – or using the Dome9 service (I’m hoping to add Unix support soon).
I chose to write this one in Python as the cross-platform language of choice, and it’s compatible with Python 2.7 to 3.4. One feature of this script is that you can optionally configure it to run another Python script whenever a client connects to the honeyport. The client’s IP will be passed to the called script as an argument, allowing you to do whatever you want with it. The script’s output is then sent back to the connected client before they are blacklisted.
Check it out on GitHub, improvements and additional ideas are welcome!
Honeyport Script Dome9 Blacklist TTL Update
Dome9 just introduced the ability to set a time-to-live (TTL) option for blacklisted IPs, something I may have bugged them for about once or twice! This is nice as it allows items on your blacklist to expire after a pre-determined amount of time instead of living on in perpetuity. It’s particularly beneficial when you run something like my Honeyport that can end up blacklisting over 400 unique IPs in about two months — it saves having to go in and manually remove blacklisted IPs periodically.
I’ve updated my Honeyport script to include the option to set a TTL on blacklisted IPs when using Dome9. Note this doesn’t yet work when using IPtables as it doesn’t have an easy TTL-style option for rules. This functionality for IPtables is on my TODO list.
Check out honeyport-0.2.sh here!
Linux Bash Ncat Honeyport Script with IPTables and Dome9 Support
After securing systems by hiding them completely from the network/internet using Single Packet Authorization, I’ve recently been interested in doing more so-called ‘active’ defense, by implementing solutions to delay, confuse, or thwart attackers. Completely hiding one’s system is not always feasible (ie. in the case of an internet-facing server), and monitoring, apart from being purely reactive, is not always easy and requires the involvement of a human. An alternative to these is to do some automated active defense. One simple tool in the bag of active defense tricks is the honeyport. Read more
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