Latest changes

This page contains the most recent changes to the blog.

How to compare two directories and find the differences
How to find symbolic links that point to a directory
Monitoring USB communications using usbmon interface
How to see the creation date of a file
The Most Influential Linux Security Blogs
SSH server configuration
journalctl cheat sheet
What is the ‘toor’ user on FreeBSD?
What’s New in Lynis 2: Features
How to see BIOS details
How to find the specific cause of a tainted kernel
How to show all installed packages on Ubuntu
What is a tainted kernel
How to see the default gateway on Linux
How to see open ports on Linux
How to see which process is using a port
How to see the TTL value of a DNS record
How to start and enable a unit with systemctl
How to show failed units with systemctl
How to see the last X lines with journalctl
How to disable a systemd unit with systemctl
Systemd timers
How to see the number of open connections on Linux
Swap memory information
How to see when a process was started
How to see when the system was started (uptime)
How to see active connections and bandwidth usage on Linux
Troubleshooting CPU usage
Strip one or more characters from a variable or output
Prompt for user input in a shell script
Making scripts (more) secure and safe
Check if a directory or file exists
How to show network TCP statistics and counters
Show to clear the DNS cache with systemd
How to see the available hard disks
How to see memory information such as type and speed
How to see hard disk specifications and details
How to see CPU details
How to list all USB devices
RSS is cool! Some RSS feed readers are not (yet)...
tcpdump cheat sheet
Using File ACLs on Linux for Additional Security
Upgrading External Packages with unattended-upgrade
Using encrypted documents with vim
Vulnerable packages on FreeBSD: pkg audit
Methods to find the Linux distribution and version
dmidecode cheat sheet
How to securely delete a file and its contents
find cheat sheet
Understanding the output of the stat command
tar cheat sheet
Check for a required reboot on Debian and Ubuntu systems
Auditing systemd: solving failed units with systemctl
Find differences between two daily Lynis audits
ip cheat sheet
How to see errors on dropped packets on a network interface on Linux
systemd cheat sheet
systemctl cheat sheet
strace cheat sheet
ss cheat sheet
curl cheat sheet
du cheat sheet
AWK cheat sheet
lsof cheat sheet
Protecting the browser: Web of Trust
Protect Linux systems against SSLv3 Poodle vulnerability
Finding boot logs in systemd journals
List installed packages on a Linux system
How to find the biggest directories on disk
BPFILTER: the next-generation Linux firewall
How to create custom tests in Lynis
How to deal with a compromised Linux system
Configure HSTS (HTTP Strict Transport Security) for Apache and Nginx
Discover to which package a file belongs to
Auditing Linux processes: The Deep Dive!
Linux tools to bulk rename files
Tuning auditd: high-performance Linux Auditing
Secure Software Development: CII Best Practices
Using Ed25519 for OpenSSH keys (instead of DSA/RSA/ECDSA)
GPG key generation: Not enough random bytes available
Unix security audit: Perform an audit in 3 minutes
Linux vulnerabilities: from detection to treatment
Postfix Hardening Guide for Security and Privacy
Linux server hardening and best practices
Plus sign in ls output
Using xattrs or Extended Attributes on Linux
Linux History: How Dot Files Became Hidden Files
Linux system hardening: adding hidepid to /proc mount point