Hello everyone,
Ever feel like your Linux system could use a little extra armor?
Recently I wrote about Qubes OS, but sadly my Intel processor just can’t handle it.
I really like my current setup with CachyOS. That’s why I needed another solution because using a virtual machine to separate each application provides great isolation from the rest of
the system.
First, I thought about installing a very lightweight OS on VirtualBox for using Firefox, but this isn’t practical because of too many extra steps just to use Firefox. Then I
read about Firejail.
Firejail can put any program on Linux into a sandbox, which means that the app inside the sandbox is isolated from the rest of the system - similar to a virtual machine, but not the same.
Because a virtual machine creates a whole new OS, Firejail just puts the app inside a sandbox. It’s still a great way to fortify myself. So in this blog post, I like to share my
configurations on Firefox and how I used Firejail to simplify and fortify my Linux.
I am going to start with my Firefox setup. I use those Extensions:
Extensions are fantastic, but safeguarding my own data is most important.
I've spent time on the Microsoft subreddit, and it felt like daily posts about compromised accounts — a stark
reminder of online threats.
I've explored various email providers, and yes, I know many people criticize Microsoft. But their privacy settings for email truly impress me.
Microsoft allows you to create aliases, essentially multiple email addresses that share a single mailbox.
I've gone a little overboard with this! I have aliases specifically for
Bitwarden and my Microsoft account – never used for anything else, registered nowhere except within Microsoft.
Then there are aliases for different purposes: one for my blog, another for private use, even ones for registering on various websites. The beauty is, all these emails land in the same
inbox. And here's the clincher: you can choose which alias grants access to your accounts. So, none of the addresses I use for website registration can ever be used to log into
Bitwarden or Microsoft—keeping my login information incredibly secure when combined with 2FA.
Finally, I’ll tell you how I fortified my Cachy OS with Firejail. Normally, to start an application via Firejail, it’s needed to open a terminal and write the command – for example:
“Firejail firefox”. But I’m not only using Firefox; I’m a fox by myself! I can’t take all the credit, but with help from ChatGPT, I created a file to make an icon that automatically
opens my desired app via Firejail, making those previous steps completely useless.
I will explain the file and show it on the example of Firefox.
[Desktop Entry]
Name=Firefox (Firejail)
Comment=Browse the web with Firefox in a Firejail sandbox
Exec=firejail firefox
Icon=firefox
Terminal=false
Type=Application
Categories=Network;WebBrowser;
You can create a similar setup yourself! Use a text editor like nano to create a new file and paste this code into it. The script is fairly straightforward and mostly
self-explanatory. The crucial line is "Exec=firejail firefox", which executes Firejail with Firefox as the target application every time you click the newly created icon named
"Firefox (Firejail)". The "Terminal=false" setting ensures that the application runs as a graphical program, not within a terminal window.
And here's the best part! You can create these types of files for any application you want to run in Firejail. Simply change "firefox" to the command you want to execute, and you have an icon for secure, isolated app usage.
Remember, no security setup guarantees complete protection. There's always a possibility of compromise, no matter how robust your defenses. However, by implementing these measures, you significantly reduce your risk and make it much harder for attackers to succeed. Stay informed about potential threats and remain vigilant, because Cybersecurity is an ongoing journey!