What’s the name of the distro?
Not so much a distro as most decent distros now include SELinux (Security Enhanced Linux). Allows for the introduction of the concept of mandatory access controls and is a security module that is enabled.
https://en.wikipedia.org/wiki/Security-Enhanced_Linux
Here is an NSA sponsored web page that identifies SELinux distros
https://www.nsa.gov/research/_files/selinux/papers/x/img6.shtml
I think the actual list may be larger than that assuming one does the work to implement the SELinux mods as add ins. I know Red Hat Enterprise Linux has it. Here is a URL that talks about some others:
http://searchenterpriselinux.techtarget.com/answer/SELinux-on-other-distros-not-just-Red-Hat
OpenBSD is also a good alternative.