eve2pcap – Eve Packet and Payload Conversion to pcap

I’ve added a new tool to my idstools package to convert the packets (or the payloads) found in Suricata eve logs to a pcap file.

To just grab the script, download eve2pcap.py and make it executable, or to install the complete idstools package (will install as idstools-eve2pcap):

pip install –upgrade https://github.com/jasonish/py-idstools/archive/master.zip

Usage is pretty simple:

./eve2pcap.py -o output.pcap /path/to/eve.json

Or to use the payload field instead of the packet field:

./eve2pcap.py -o output.pcap –payload /path/to/eve.json

For straight packet conversion no dependencies are required other than Python and libpcap. Scapy is used for conversion of the payload field, so make sure to install it before trying to convert the payload.

It is also important to note that eve logs do not contain all the information to recreate the packet headers, so when converting payloads to pcap the headers are “manufactured” and may not always produce the best packet for the payload, so YMMV.

eve2pcap – Eve Packet and Payload Conversion to pcap

Suricata Quick Start for Fedora 21 and 22

Fedora Linux 21 and 22 have Suricata 2.0.8 in their default repositories making it very easy to get started.  The following was done on Fedora 22, but should be applicable to Fedora 21 as well.

Install Suricata

yum install suricata

Configure Interface

By default, Suricata will be configured to run on eth0, if you need to change this, edit /etc/sysconfig/suricata and change eth0 to your desired interface.

Start Suricata

To start Suricata one time:

systemctl start suricata

To have it restarted on each boot:

systemctl enable suricata

But you’ll probably want to have it started after your network is ready. This can be done by including network-online.target in the unit file /usr/lib/systemd/system/suricata.service

Description=Suricata Intrusion Detection Service
After=syslog.target network-online.target

ExecStart=/sbin/suricata -c /etc/suricata/suricata.yaml $OPTIONS


Verify That Suricata is Running

Even though we have not downloaded any rules yet, Suricata will still log HTTP requests, DNS requests, TLS certificates and SSH connection by default. These can be observed by monitoring /var/log/suricata/eve.log.

tail -f /var/log/suricata/eve.log

Download Some Rules

To get the most out of Suricata you will want to download some rules. The Emerging Threats Open rules are freely available and can be installed with the following commands:

cd /etc/suricata
curl http://rules.emergingthreats.net/open/suricata-2.0/emerging.rules.tar.gz | tar zxvf -
systemctl restart suricata
Suricata Quick Start for Fedora 21 and 22

Another IDS rule downloader – rulecat

I didn’t mean to do it, but I created yet another tool to download IDS rules, with a specific focus on Suricata.  Like some other people, I’ve always used my own scripts for downloading rules instead of using existing tools, and I finally pulled some of that together and dropped it into my idstools project.


With pip (as its written in Python):

pip install idstools

From source, https://github.com/jasonish/py-idstools/releases/download/0.5.0/idstools-0.5.0.tar.gz, where idstools-rulecat can be run from the exploded tarball without installing (also works with a git clone).


Probably the simplest usage, assuming you have Suricata already installed is something like:

idstools-rulecat --rules-dir /etc/suricata/rules

This will download the ET Open rules for your version of Suricata and drop them in /etc/suricata/rules.

Other useful output options include:

  • –merged to merge all the rules into a single file making it easier to include into your suricata.yaml.
  • –yaml-fragment to dump a fragment of YAML for inclusion in your suricata.yaml that lists each rule file downloaded.

Of course you can also disable, enable and modify rules.  To get sample configuration files for doing so, run:

idstools-rulecat --dump-sample-configs

which will drop the following files into your current directory:

  • disable.conf – allows disabling of rules by ID or regular expression.
  • enable.conf – allows enabling of rules by ID or regular expression.
  • modify.conf – rule modifications
  • threshold.in – an input threshold.conf that idstools-rulecat will expand (experimental)

As with many Python programs using the argparse module, a configuration file can be created by dropping command line arguments in a file and calling idstools-rulecat like:

idstools-rulecat @/path/to/rulecat.conf

For example, I use a rulecat.conf like:

--post-hook=sudo kill -USR2 $(cat /var/run/suricata.pid)

Note the –etpro which will ET Pro rules instead of the ET Open rules.

For full usage, head over to http://idstools.readthedocs.org/en/latest/tools/rulecat.html.

This is a work in progress, and is primarily being developed to satisfy my needs, perhaps it will be useful to others as well.

Another IDS rule downloader – rulecat

Suricata with EveBox on a Honeypot

I recently installed some honeypot software and am logging the traffic with Suricata into Elastic Search with Logstash. I know its a bit of a risk to expose Elastic Search like this, but I thought it could make a good demo for EveBox.

To check it out head over to http://evebox.codemonkey.net/ with the username “evebox” with the same as the password.

This probably won’t be up for too long, it will depend on how useful the honeypot is to me at this time.

Suricata with EveBox on a Honeypot

Suricata RPM for EL and CentOS 7

I’ve taken the Suricata package as found in Fedora and rebuilt it for CentOS 7. This should be similar to how the package would exist in EPEL (and hopefully it makes its way there).

To get the package with yum, first install the yum repository package (note: you must already have EPEL installed):

rpm -Uvh http://codemonkey.net/files/rpm/suricata/el7/suricata-release-el-7-1.el7.noarch.rpm

then install Suricata:

yum install suricata

To just get the package, head over to http://codemonkey.net/files/rpm/suricata/el7/.

Suricata RPM for EL and CentOS 7