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OSINT

Email to Profile: Social Media Search and Free Lookup Tools

Introduction Connecting an email address to a real person can reveal valuable insights. With email-to-profile...

OSINT

Advanced Free Email Lookup and Reverse Search Techniques

Introduction Email addresses are often the keys to digital identities. With the right tools, you...

How to Use Pentest Copilot in Kali Linux

Introduction Artificial Intelligence is changing how cybersecurity professionals work, especially in penetration testing. Tools that...

free Command in Linux: Check Memory Usage and Interpret Output

By Cyber Defence on August 6, 2026

The free command in Linux gives you a quick summary of RAM and swap usage. It reads from /proc/meminfo and displays the data in a single table with one command. This guide covers how to use the free command in Linux and what each column in...

diff Command in Linux: Compare Files and Create Patches

By Cyber Defence on August 6, 2026

The diff command in Linux compares two text files line by line and shows the lines that differ. When files are identical, it produces no output. That behavior is useful in scripts — you can test the exit code without reading any...

Flush DNS Cache on Windows, Linux, and macOS: Quick Commands

By Cyber Defence on August 6, 2026

DNS cache is a temporary database your OS and browser build as you browse. Each time you visit a website, the domain-to-IP mapping is saved locally, cutting out the round trip to a remote DNS server on repeat visits. Stale entries are the most common reason to flush the DNS cache: a server moves to a new IP, but your OS or browser still routes to the old address. This guide covers how to clear the DNS cache on Windows, Linux, and macOS, and how to flush the separate cache stored inside Chrome and Firefox. Flush DNS Cache on Windows The command is the same on Windows 10, Windows 11, and earlier supported releases. Open Command Prompt with administrator privileges. Type cmd in the Windows search bar, right-click Command Prompt, and select Run as administrator. Run the flush command: A successful run prints: ipconfig /flushdns clears all entries from the Windows DNS Resolver Cache. The OS makes fresh DNS queries on the next domain lookup. Clear the DNS Cache on Linux Linux does not cache DNS entries at the OS level by default. DNS caching only happens when a dedicated service is installed and running. Before flushing, check which caching service is active on your system. systemd-resolved – the default resolver on Ubuntu, Fedora, and most modern desktop distributions. Check whether it is running: If the output is active, flush the cache with: The command produces no output on success. Older guides show sudo systemd-resolve --flush-caches – that command is deprecated on modern systems and replaced by resolvectl. DNSMasq – a lightweight caching nameserver common on embedded and router-style Linux systems. Restart the service to clear its cache: Nscd – the Name Service Cache Daemon, found on older Red Hat and CentOS systems: Clear DNS Cache on macOS and...

Change User Password in Ubuntu: Command Line and GNOME GUI

By Cyber Defence on August 5, 2026

Using a strong, unique password for every account is one of the most effective security habits. A compromised password accounts for a large share of account breaches, and reusing passwords across services means one breach cascades into many. This guide...

Email to Profile: Social Media Search and Free Lookup Tools

By 0xSnow on November 3, 2025

Introduction Connecting an email address to a real person can reveal valuable insights. With email-to-profile searches, social media lookups, and reverse search tools, you can uncover linked accounts, public posts, and verified identities. This process is common in cybersecurity, recruiting,...

Advanced Free Email Lookup and Reverse Search Techniques

By 0xSnow on November 3, 2025

Introduction Email addresses are often the keys to digital identities. With the right tools, you can uncover social media profiles, online activity, and even business records associated with an email. This process, known as email lookup or reverse email search,...

How to Use Pentest Copilot in Kali Linux

By 0xSnow on November 1, 2025

Introduction Artificial Intelligence is changing how cybersecurity professionals work, especially in penetration testing. Tools that once required manual effort are now becoming smarter and more efficient. One of the most interesting AI-assisted tools available today is Pentest Copilot, developed by...

How to Use the Windows Registry to optimize and control your PC.

By Tamilselvan S on October 30, 2025

The Windows Registry Editor lets you easily view and control critical Windows system and application settings. It acts as a central hub, storing configuration information for your hardware, software, and personal preferences. Type regedit in the Start menu or the...

MQTT Security: Securing IoT Communications

By 0xSnow on October 30, 2025

In the rapidly expanding Internet of Things (IoT) ecosystem, billions of devices are constantly exchanging data from smart home appliances and industrial sensors to connected vehicles and healthcare monitors. Behind this seamless communication lies a lightweight protocol that powers most...

Change Timezone on Ubuntu: timedatectl and Desktop GUI Guide

By Cyber Defence on July 31, 2026

The correct timezone affects more than the clock on your screen. It drives cron job scheduling, systemd timer execution, log file timestamps, database record timing, and SSL certificate validity checks. A mismatched timezone can cause scheduled jobs to fire at the wrong hour and make log timestamps impossible to match with real-world events. This guide shows how to change timezone on Ubuntu using the timedatectl command (the recommended approach for servers and remote machines) and through the graphical Date & Time settings on desktop systems. The steps apply to all current Ubuntu releases including 24.04 and 26.04. Check the Current Timezone Before You Change It Run timedatectl with no arguments to see the active timezone and clock status: Sample output: A few fields worth understanding: The timezone is implemented as a symlink. Confirm the active timezone by checking where /etc/localtime points: The final component after /usr/share/zoneinfo/ shows the current timezone name. Change Timezone on Ubuntu Using timedatectl First, identify the exact name of your target timezone. Ubuntu uses a Region/City format, not UTC+N offsets. Region/City names are preferred because they automatically account for Daylight Saving Time transitions — a fixed offset like UTC+5:30 becomes wrong when clocks change. List all available timezones: Narrow the output with grep to search by region or city: Timezone names are case-sensitive. Copy the name exactly as shown in the output. Apply the new timezone: Verify the change: The Time zone line now shows the new zone and its current offset. The change takes effect immediately and persists across reboots. Unlike a manual symlink change, timedatectl updates both /etc/localtime and /etc/timezone — the second file is required by legacy tools and some older applications that do not read from /etc/localtime directly. Change the Timezone in Ubuntu Desktop Using the GUI Open Settings from the top-right system menu and select System, then Date &...

Upgrade to Ubuntu 26.04 from 25.10 and 24.04 LTS: Complete Guide

By Cyber Defence on July 31, 2026

Ubuntu 26.04 LTS “Resolute Raccoon” arrived on April 23, 2026 with Linux kernel 7.0, GNOME 50, Python 3.14, PHP 8.5, Java 25, TPM-backed full-disk encryption, post-quantum cryptography in OpenSSL, and a Wayland-only GNOME session. You can upgrade to Ubuntu 26.04 directly...

Install PHP on Ubuntu 26.04: Apache, Nginx, and Multiple Versions

By Cyber Defence on July 31, 2026

PHP 8.5 is included in Ubuntu 26.04’s default repositories and is the recommended version for new PHP applications. Many popular tools including WordPress, Laravel, and Magento run on PHP, making it one of the first packages configured on LAMP and...

Install Ubuntu 26.04: Bootable USB, Partitioning, and First Steps

By Cyber Defence on July 31, 2026

Ubuntu 26.04 LTS “Resolute Raccoon” was released on April 23, 2026 with Linux kernel 7.0, GNOME desktop, and standard security support until April 2031. A clean install gives you a known-good starting point on new hardware, when replacing another operating system, or when an upgrade path is not practical. This guide walks through how to install Ubuntu 26.04: downloading and verifying the ISO, writing a bootable USB drive, completing the installer, and doing the initial setup after the first boot. Before you start: You need a USB drive with at least 12 GB of free space. Back up any existing data on the target machine — the installer can erase the entire disk. Install Ubuntu 26.04: Download the ISO and Create a Bootable USB Download the desktop ISO from the official Ubuntu downloads page. The file is ubuntu-26.04-desktop-amd64.iso at about 6.1 GB. Verify the download before writing to USB. A corrupted ISO causes installer crashes that are difficult to diagnose. Download the checksum file and compare it: The output should show ubuntu-26.04-desktop-amd64.iso: OK. On Windows, use Get-FileHash in PowerShell. On macOS, use shasum -a 256. Write the ISO to a USB drive. Use Rufus on Windows, balenaEtcher on macOS, or dd on Linux. On Windows with Rufus: select the ISO, keep Write...

Install Kubernetes on Ubuntu 26.04 with kubeadm and containerd

By Cyber Defence on July 31, 2026

Kubernetes is the standard platform for running containerized workloads across multiple servers with self-healing, rolling updates, and built-in service discovery. kubeadm is the upstream tool for bootstrapping a minimal cluster on plain Linux servers without managed cloud infrastructure. This guide...