If it’s Trixbox the OS is most likely CentOS, which indeed is “some sort of linux flavor.” You’re running very old versions of Asterisk and FreePBX (especially Asterisk). You should be aware that Trixbox has forked FreePBX, which in simple terms means that they are NOW running an unsupported variant of FreePBX.
My advice to you would be this: First, spend some time learning about the system - there is a free e-book called Trixbox without Tears that will help you get up to speed. At some point, when you feel you know your way around a bit, you may want to migrate to a newer, currently supported distribution such as Elastix, PBX in a Flash, Fonica PABX, or AsteriskNOW instead of Trixbox (there are also “… without Tears” books available for the first two mentioned). All of those distributions include CentOS, FreePBX (the genuine un-forked version), and Asterisk - the only real difference between them is in the “extras” they include and the target audience - some are designed for people with less experience. I personally like Elastix, because although it’s not perfect, it does seem to strike a balance between not being too hard to use, and yet not taking over your system in ways you might not want it to. But everyone has their own preference.
Your problem is that you don’t have the latest security patches, so your system may be rather vulnerable to attacks. So don’t think you have months to learn about the system you have - ideally you want to migrate to something newer ASAP. But you can’t do that until you learn enough to know how to save the current settings and apply them to whichever new distribution you choose. If I were you I’d build the new system on a different box if possible, so you can refer back and forth between the two systems while migrating. If that’s not possible, then use Firefox and get a browser extension (such as Screengrab) that lets you save images of entire configuration pages, so you have something to refer back to when you are trying to rebuild the system. Note that once you insert the installation disk for a new distribution, it will reformat your hard drive and start from scratch (which is really the best way to do it, all things considered) so you need to save your screenshots and other configuration backups to some other system on the network. If you have room I’d do a full system backup, just in case there is some file you miss that you later find that you need.
I know this is a lot to lay on you and it’s probably a bit confusing, but the problem is you have to learn about the system you have enough to be able to migrate it to something newer, more secure, and (preferably) not using a forked version of FreePBX, but for the sake of security you need to learn how to do that fairly quickly. So, time to hit the e-books (and remember, Google is your Friend!).
P.S. I may have missed something or made this more complicated than necessary, so you may want to watch this thread and see if anyone else chimes in with advice.