Sometimes the old ways are the best ways (support for BASE and Syslog_Full output)

Hello AS/snort users,

Got two new features in this latest build of autosnort.

First and foremost is support for the BASE web interface. BASE is by and far one of the older and more well-known web interfaces for snort alerting. While the interface isn't going to win for prettiest interface, it is by and far very functional. Some of the cool things include the ability to download alerts as pcap and actual tshark/pcap parsed output for each alert.

This has been added as an installation option in the interface selection menu. The installation is painless and straight forward. After the system reboots, just point your browser to http://[your ip]/base.

The web page initial setup will check for all of the required pre-requisite settings on the first page. On the second page, it will ask you where adodb, a pre-requisite package, is installed. Autosnort and most linux distros install adodb to /usr/share/php/adodb (put that in for the path to adodb). It will also, of course ask you for database information and credentials:
database name: snort
database host: localhost
database port: 3306 (can leave blank if you'd like)
database username: snort
password: (the snort database user's password)

Unless you have an archive database configured, leave that part blank.
On the last page, it will ask if you want to set up auth to get into the web page to review events. That is entirely up to you.

After that, you should be all set to get events to the BASE web interface.

The next feature I have to announce is support for syslog output as another output interface choice. I've added a child script that configures barnyard2 to output to syslog_full format to port 514/udp. I have not FULLY tested this feature, but preliminary tests show that splunk picks up and parses the events with no issues whatsoever. A couple of troubleshooting recommendations:

-Ensure that the sensor's management interface, if it is firewalled, has port 514/udp open and allowed outbound.
-Conversely, ensure that your SIEM or syslog aggregator has port 514/udp open inbound to accept events -- I hosted splunk on a CentOS box and was puzzled why tcpdump says we were sending events out, but they were never making it to be indexed by splunk. I ran system-config-firewall-tui and added a rule for 514/udp inbound (and port 8000/tcp inbound for the actual web UI), and everything was fine.

The child scripts have been made available to Debian, Ubuntu and CentOS.

One last thing:

I've made some minor changes to the script at the recommendation of maintainer of the barnyard2 project. Instead of using sed to modify the copy of barnyard2.conf included with the barnyard2 source, I'm making the script generate a barnyard.conf on-the-fly.

- the script keeps a copy of the original barnyard2.conf in /usr/local/snort/etc/ named barnyard2.conf.origin
- the script generates a barnyard2.conf with only the directives necessary to run barnyard2 (e.g. where are the reference and classification config files, the gen/sid-msg.map files, input format to accept, output format to output to, etc.)
- if you choose to configure output to syslog format, the child script disables output to the database automatically.

As always, the scripts are up on github, along with updated READMEs. Previous versions are available in the Previous_Rel directory as well.

Happy Hunting..

DA_667

New AS release, New init scripts, bug fixes and more!

Hello AS users,

Got a lot to talk about today, so let's get down to business:

First and foremost I've finally gotten around to writing half-decent documentation for autosnort. I've pushed a pdf file to github featuring documentation with screenshots on how to install Autosnort via vmware player, including an interesting hack on how to get bridging to work on multiple interfaces on vmware player 5.

I chose CentOS as the vmware player operating system, but the instructions should be easy to follow for Debian Ubuntu or Backtrack. Any major differences were noted. All said and done it was about 23 pages of documentation with screenshots peppered in.

I focused on using VMware player this time around, and generally speaking the VMware player guidance can be used just as well for VMware Fusion or Workstation. I may do an alternate document for ESXi and/or Virtualbox in the near future.

I've also included general troubleshooting steps and things you *should* see after running autosnort.

Next in line is an update to the autosnort script for Debian, Ubuntu, and CentOS. Banyard2.13 BETA2 has changed how barnyard2 behaves. As a result of this, I had to change how arguments are passed to barnyard2 in Autosnort. The details are available for each operating system's readme files. Suffice to say, everything works fine now.

Finally, I've gotten around to testing and posting init scripts for Ubuntu and Debian to control snort and barnyard2. The Ubuntu and Debian init scripts support start, stop and restart functions and are pretty easy to implement. Implemtation details are also available via the Readme files for Ubuntu and Debian Autosnort scripts, but suffice to say, its incredibly easy.

I may release a modification to the init script that detects if you installed aanval and automatically start/stop the BPUs along with snort and barnyard2, but that will come a little later.

The documentation, new scripts, readmes and init scripts should all be available via github as of now.

Cheers,

DA

Redhat/CentOS init script!

Hello AS and regular snort users,

I wanted to announce that I have developed an init script compatible with CentOS/Redhat variants for autosnort installations (of course, this script can easily be adapted to other snort snort installations.

This init script can be used to replace /etc/rc.local as the primary method of starting up snort and barnyard2, and includes the added bonus of allow you to start/stop/restart snort and barnyard2 without requiring a reboot or sourcing /etc/rc.local if you need to make changes to snort or barnyard2. To add this script to CentOS 6.x perform the following tasks as root (or via sudo/root permissions):

    1. Copy the snortbarn script to /etc/init.d
    2. Edit the variables near the top of the script to suit your snort installation (the only variable that you should need to modify is the snort_iface variable if you installed snort/barnyard2 via autosnort)
    3. Make the snortbarn script is executable for the root user (chmod 700 snortbarn)
    4. Run chkconfig --add snortbarn
    5. Remove the entries for ifconfig, snort, and barnyard2 from /etc/rc.local (note: you may want to make a backup of the rc.local script in case you run into bugs/problems with the init script!)
    6. Kill your current snort/barnyard processes that ran from rc.local (killall snort && killall barnyard2)
    7. Run the command "service snortbarn start"
    8. check the process list to ensure that snort and barnyard2 are running after calling the init script. ( "ps -ef | grep snort" will return snort and barnyard2, if either/both processes are running. If only one process or the other is visible, something is wrong)

Troubleshooting steps: I'm not entirely sure why but there are CRLF/LF formatting problems with this script. If you get a bunch of errors stating that a file/command doesn't exist, try running dos2unix on the file to resolve the CRLF/LF errors.

If you install the init script and upon reboot find that only the snort process is running, it is because the init script for snortbarn ran BEFORE the init script for mysqld ran. To Determine when mysqld is configured to run it its runlevels, check /etc/init.d/mysqld. You'll want to pay attention to this line in particular:

# chkconfig: - 64 36
the first number, 64 indicates what number the rc startup script will get on startup. Linux rc scripts determine what services run or are killed on a particular run level. Every rc script as a K for Kill order, an S for Start order, followed by a number and the name of the symlinked script from /etc/init.d. RC scripts are read in numeric order. So if the rc script for snortbarn has an S number lower than 64, it will run before mysqld. snort will start up fine, but barnyard fails because it has no database to connect to.

To remedy this, you can modify the /etc/init.d/mysqld script to have a lower number than the snortbarn script in any of the /etc/rc[2-5].d directories, or modify the snortbarn script to have a higher number than the mysqld directory. This is a little confusing, so let's look at an example:

run this command: ls -al /etc/rc?.d/S*snortbarn

this command shows you each runlevel snortbarn is configured to start on.

now, run this command: ls -al /etc/rc?.d/S*mysqld

this command shows you the runlevels mysqld is set to run on. Don't worry about how many results you get.

If mysqld's number is higher than snortbarn's number, the mysqld process will not be running before snort and barnyard are configured to run. No database running means barnyard2 won't run. Let's say snortbarn had a number of 63, and mysqld has a number of 64. edit /etc/init.d/mysqld and change the chkconfig to something like this:

# chkconfig: - 62 36

save your changes and run chkconfig --add mysqld. This should fix the problem.

I've added the above documention to the other notes section of the CentOS readme. The snortbarn script is now available via github.

Special Note: Would like to thank Tactical FLEX/Aanval for hosting the initial version of this init script that I based this one off of. Would also like to thank Mike Miller for the initial idea of moving away from rc.local and building out a legitimate init script for autosnort.

Happy Snorting,

DA667

Hammering out Aanval

Hello Autosnort Users,

Today I would like to announce support for Tactical Flex's Aanval Web Console on CentOS and Debian platforms in addition to last weekend's Ubuntu release

I've implemented the same changes for the CentOS and Debian scripts that I've implemented on the Ubuntu script, namely the modularization of autosnort, starting with the web interface choices snortreport and aanval.

I've updated the readme files in each operating system's directory to more of a "release notes" format, that will be easier to read and follow.

One issue that I'd like to write about that I encountered while working on getting Aanval running on CentOS in particular is SELinux. Most people see SELinux as an annoying hindrance that keeps them from getting done what they want to get done. I use to be one of those people as well. But with a little bit of research, most problems with SELinux can be resolved easily, without disabling it or setting it to permissive mode (making it essentially useless).

I ran into a problem during aanval installation where it failed to connect to the mysql database on localhost with the creds I gave it. Thinking I fat-fingered the creds, I did it again and it immediately failed again.

At this point, I check the logs. Nothing interesting in /var/log/messages or the httpd error_logs, so I move to the audit log. For those of you who are not aware, SELinux usually logs to /var/log/audit/audit.log. It's log format is pretty strange, but its easy enough to pick out the relevant pieces to determine if SELinux is interfering with what you you need your system to do. run tail -f on audit.log and try entering the database credentials again and an entry pops up for SELinux, denying access to 3306/tcp for the httpd process. I do a google search for a small portion of the audit log message, and immediately get a relevant result. Long story short, run this command:

setsebool -P httpd_can_network_connect_db 1

 This explicitly states to SELinux that the httpd process requesting connections to the database/database port are perfectly fine. Always remember: disabling SELinux is NEVER the answer.

Happy Easter and Happy Snorting,

DA667