Linux Essentials For Hackers - #8 - Enumerating Distribution & Kernel Information

Key Takeaways

hey guys welcome back to the linux essential series for hackers in this video we're going to be taking a look at how to enumerate uh system information on linux now you might be wondering what exactly do you mean here well i'm simply referring to uh important information about your system and the user currently logged in as just information that you might need when you're currently logged onto a system and you might want to know more about what you're dealing with all right so let's get started now the first uh the the first thing we need to do is we need to find out what user we're currently logged in as and the host name and the user id etc etc all right so let's get started with that so the first thing i want to know when i'm logged in is who am i exactly and that tells me the current user that i'm logged in as and then if i type in host name uh that again gives me the current host name of this workstation or of this computer in my case it tells me i'm running uh the host name is alexis workstation now if you do want to change your uh your host name uh you can you can do so by by modifying the host name file i believe uh that's what it's called the yeah there we are and you can see that mine is set to alexis workstation or ws which is an abbreviation of workstation so you can change this and in my case i don't want to do this so i'm just going to exit out of here so that is how to find out the current user logged in as and the host name now if you want to find the user id that you're currently logged in as you can simply type in id that gives you the current use id and again of course the user you then have the group id which is quite important and the other groups that this user is currently a part of now um in regards to groups and the groups that a particular user may be uh part of uh the way to enumerate this information is by typing in groups and then the name of the user so we can type in groups alexis and once we hit enter again it tells us uh the user lexis is a part of these groups so it's a part of the group alexis uh sudo among the other ones here that are essentially system uh system accounts here that you or system groups that uh really have to do it just permissions to a particular service um so that is basic user enumeration now let's talk about a little bit about the system and enumerating information like um like your uh like your linux distribution uh the version stuff like that so uh i'm currently using a debian system or i'm using ubuntu so again it's based on debian so the the practices are all the the techniques and the commands are quite similar on both ends now in dealing with uh you know systemd based distributions uh and all of course red hat based distributions the process is going to be slightly different and i'll explain why and how um so on linux if you on a on on on debian or on ubuntu if you want to enumerate your linux ker if you want to enumerate your linux distribution version and the name you simply type in lsb release a and of course lsb is a utility and you may not have it installed but again it comes with um with db and ubuntu by default so again that tells us the distributor the distributor id the description again ubuntu 18.04 0.3 lts the release name sorry the release version and the code name here which in this case is bionic beaver so again you can also use the check the contents of the issue file so if we type in cat etsy issue you can see it tells us the same thing here so that is for debian based distributions now um when dealing with system d distributions like um centos arch red hat also debian to to some extent you can also use the you can also take a look at the content within the os release file which will also enumerate on debian as well but i just wanted to explain that so you guys don't get confused all right so what you can do is just simply type in cat let's see os os release and again that gives us the information that we were looking for now on um on ubuntu and on debian if i hit enter it tells us nothing there if i then use the star wall card we hit enter that gives us the linux distribution information and a bit more information regarding the privacy policy uh support url stuff like that and now that's uh now that we've also covered the systemd uh based distributions let's talk about uh dealing with red hat now on reddit um if you want to take a look at the uh the red hat release version uh you can i believe you can find it if i type in cat hc and then you type in red hat release now i'm currently not using a red hat based distribution so that would pretty much give you the red release version um so that's basically enumerating your distribution name uh your distribution version and name um if you are using you know some of these uh distributions based on debian or the systemd based distributions like arch uh centos or red at enterprise linux so again let's talk about you know enumerating information about your processor or your cpu so you can easily do this by typing your ls cpu and we can hit enter and again that enumerates information about your cpu so it gives you information like your architecture and the instruction set um the amount of uh the amount of calls the threads per core the cost per socket the sockets uh vend id uh cpu family the model model name uh in this case it's an i5 8400 uh the stepping the the frequency here in megahertz so max and minimum as well so four gig by four gigahertz and the minimum of 800 megahertz uh virtualization and then the l1 l2 and l3 cache and so information about your cpu all right so now that we've taken a look at enumerating cpu information let's take a look at enumerating kernel uh information which is done using the u name uh we're using the unnamed command or utility which essentially stands for unix name so again if we just type in what is your name here and you can see it says prints system information and guess the name and information about the current uh kernel so using it is very very simple so if you type in your name a that displays all the information so again it gives you information about like your uh your host name the current linux kernel that's that's installed and currently running and then you have the uh you then have the instruction set here i'm going over the the important information so again we can uh we can actually take a look at the various options that are available here so again we can say if we want the kernel we if we want the kernel version here we can type in we can say you name s and that tells us the kernel that we're currently running which is the linux kernel the version here can be printed out by typing you name i believe it's your name r that's the kernel release so in our case it's version 4.15 which i believe is stable not too sure um and then if you want again if you want the the information about the the instruction set for your processor you can type in your name you name p again that gives you the instruction set in our case x864 uh and then if we want the hardware platform we can type in your name i so we can say you name i the hardware platform again that's the that's uh the information in regards to the architecture and then the operating system uh we can say you name o and it enter gnu linux so again just basic information regarding your system but the key bits of the important pieces of information here are your kernel and the instruction set of course so that's essentially all the information that you might want to enumerate regarding your system or you might be interested in now dealing with with disk usage and disk and disk usage disk space i'll be making a separate video on that so you guys can stay tuned for that but in regards to your system this these all the commands that you can use to find information about your the current user that's logged in uh so again if i type in who again that tells me the current users that are logged in in my case it's uh the only user is alexis so that's just an additional tidbit so again we've covered uh you know the user id the group id and we've also covered enumerating distribution information and the kernel information so that's pretty much going to be it for this video and i'll be seeing you in the next video