You’re cruising through your server’s inner network one fine day, when all of a sudden you notice an unfamiliar name accessing your files. This user may have come through SSH, or any other access method, but no matter the entry port, you certainly don’t want them accessing your files. Before panic sets in and you find yourself pulling the plug on your hard-earned hardware, use the following steps to first ensure that you do have a hacker onboard. Only when you’ve made certain should you blow the whistle—remember that neither customers nor colleagues appreciate a Boy Who Cries Wolf.
Did You Forget A User?
Think about it: Did you create a user with this designation, and then forget about it as the seasons rolled by? Perhaps you left a user behind a long time ago with a weak password, or just haven’t seen this user log-in for a while, and are now experiencing an uncomfortable case of deja vu.
Is This An Authorized Robot?
Remember that many of your other servers, such as your database server or your web server, operate within the system as “false” human users. There are also several different services running under the hood that do their jobs in this manner. Before freaking out about a human intruder, check the designation of the “hacker.” If it’s something similar to nobody, noname, sys, or apache, then you’ve not got a problem, just a working robot. If you’re unsure, but think the user might still be a script, do a quick Google search for the user’s name.
What Are They Doing In There?
The next step is to check what the user is actually doing: Are they running a script or program you’re familiar with? This is where things start to heat up, in a software sense: If the user is running a standard application like Apache, then don’t worry your pretty little head. However, if they’re operating a script you’ve never seen, it’s time to do a bit more digging—you may actually have a real intruder on your hands.
What To Do If Nothing Else Has Worked
If you’ve come this far, then you might genuinely have an intruder on your server. If so, the root user is the only one with the ability to create new accounts. With that in mind, check your root password and account for changes: Plug-ins and extras you have installed may also grant accidental access to the superuser. You may need to hire a security expert to check out your system, if there’s no obvious infiltration.