Now that you’ve reviewed the Release Notes in the previous section, you’re ready to download Security Onion! You can either download our Security Onion ISO image (based on CentOS 7) or download a standard CentOS 7 64-bit or Ubuntu 18.04 ISO image and then add our Security Onion components. Please keep in mind that we only support CentOS 7 and Ubuntu 18.04.


For most use cases, we recommend using our Security Onion ISO image as it’s the quickest and easiest method.


ALWAYS verify the checksum of ANY downloaded ISO image! Regardless of whether you’re downloading our Security Onion ISO image or whether you’re starting with a CentOS or Ubuntu ISO image, you should ALWAYS verify the downloaded ISO image to ensure it hasn’t been tampered with or corrupted during download.

See also

If you’re going to create a bootable USB from one of the ISO images above, there are many ways to do that. One popular choice that seems to work well for many folks is Balena Etcher which can be downloaded at