Installation of OSSEC HIDS is very simple, the install.sh shell script automating most of it. There are a few questions to be answered before the installation will occur, one of the most important being which type of installation is desired. It is important to choose the correct installation type: server, agent, local, or hybrid. More information on them can be found on the OSSEC Architecture page.
Note
In the following installation the commands follow the #. Everything else is either comments or output.
Download the latest version and verify its signature. Github releases may change the actual tarball downloads, so a checksum isn’t a great way to verify it.
Verify the requirements listed in Installations requirements are installed or available.
Extract the compressed package and run the install.sh script. It will guide you through the installation and compile the source (not shown).
# tar -zxvf ossec-hids-*.tar.gz (or gunzip -d; tar -xvf) # cd ossec-hids-* # ./install.sh
The OSSEC manager listens on UDP port 1514. Any firewalls between the agents and the manager will need to allow this traffic.
The server, agent, and hybrid installations will require additional configuration. More information can be found on the Managing the agents page.
Start OSSEC HIDS by running the following command:
# /var/ossec/bin/ossec-control start
OSSEC can also be installed in a more manual fashion. No modifications will be made to the ossec.conf file, so it will have to be configured after installation. The ossec, ossecm and ossecr users will still be created automatically.
After the source tarball is downloaded and extracted:
cd ossec-hids-*/src
make TARGET=<server|local|agent>
make install
Build options can still be passed to make (USE_ZEROMQ, USE_GEOIP, etc.).