Adding missing repositories for Debian

So, after installing Debian, if there is no network connection during installation, only the repositories available on the ISO will be added to the sources list. Hence, installing via simple apt command won’t be available.

Fortunately, the fix is quite straight forward and simple and it takes ~30 seconds :):

  1. Open terminal:

  1. Add the following lines:

  1. Run the update

  1. test with installing htop

  1. enjoy the easy life with linux :).


Life span of a Linux user/ basic Linux user management

Bob comes into the company and wants to use Linux as his main Operating system.

Some of the basic moments in the lifespan of his user on Linux are: user creation, group adding, SELinux user related activities, deletion, etc.

Continue reading “Life span of a Linux user/ basic Linux user management”

Fix: Fedora 25 Server stuck at “Setting up installation source” [probably Bug 1048344]

Fix: Fedora 25 Server stuck at “Setting up installation source”

Installation started, everything selected and you end up with the following screen and ongoing process of “Setting up installation source”.

Stuck at setting up installation sources fedora 25 server
Stuck at setting up installation sources fedora 25 server

Possible problem, that can cause this is related to the networking (or the lack of decent connection in this case). Probably caused by Bug 1048344, more info on which can be found here.

So after removing the virtual switch, everything continued flawlessly 😊.

Series: Security testing

Series: Security testing


  • Analyze various malware [viruses, trojans, keyloggers] in sandbox environment
  • Penetration testing [web applications, system testing]
  • Intrusion prevention/ detection system deployment, usage and testing
  • Vulnerability management
    • Testing vulnerability management solutions
    • Testing vulnerabilities them selves
  • Policy compliance

Continue reading “Series: Security testing”

Series: Gaining some Linux traction

Series: Gaining some Linux traction


  • Delve into Linux system administration
  • Practice installation, configuration, and other package/ program management tasks
  • Test networking and security
  • Gain additional experience in administering *nix systems
  • Enjoy VIM and try out EMACS
  • Gather some scattered knowledge
  • enjoy while building, breaking and fixing

Continue reading “Series: Gaining some Linux traction”

Installing PowerShell on RHEL/Fedora/CentOS based systems

Even that it may sound unusual, there are occasions when you would prefer to install PowerShell on Linux systems. For example – like me, you have access to several Linux system for practicing and no windows server/ workstations. Thanks to Microsoft’s “love for Linux”, during Satya Nadella’s reign, it’s quite easy.


  1. Add the PowerShell repository:
    1. curl > /etc/yum.repos.d/microsoft.repo
  2. Update the repo
  3. Install PowerShell
    1. yum install powershell
  4. Launch PowerShell:
    1. powershell
  5. Enjoy 🙂

VIM for Windows

Vim is a highly configurable text editor built to enable efficient text editing. It is an improved version of the vi editor distributed with most UNIX systems.


To enjoy VIM on Windows, just install the file located at:


Issues, questions and troubleshooting, related mostly to VIM for Windows:

  1. Where ot find the default VIM file location
    1. right click on the gVim 8.0 properties
    2. Check the folder for Start in
    3. Folder %HOMEDRIVE%%HOMEPATH%, means that the files can be found in C:\Users\<user name>

Getting SSH client for powershell /limited functionality/

One option for getting SSH for Windows/ Powershell is the great plugin available at


Easily installable by pasting iex (New-Object Net.WebClient).DownloadString(“”) in elevated PS window.


  1. To connect to SSH: New-SSHSession -ComputerName x.x.x.x
  2. To get the ID /index/ of the session: Get-SSHSession | fl
  3. To execute unamea on the connected machine: Invoke-SSHCommand -Index 0 -Comand “uname -a”



  1. Not useful if you want to launch applications /no VIM or Nano/,