CyberShield

  Introduction When you log into a website and stay logged in without entering your password again, it is not magic—it is handled by cookies and sessions. Understanding how cookies and sessions work is essential for learning web security, ethical hacking, and penetration testing. This guide explains these concepts in a simple and practical way. What are Cookies Cookies are small pieces of data stored in your browser by a website. They are used to remember user information such as login status, preferences, and tracking data. Key Features of Cookies Stored on the client (browser) Sent with every HTTP request Can store session identifiers Used for tracking and authentication What are Sessions Sessions are server-side storage mechanisms that keep track of a user’s activity. Instead of storing sensitive data in the browser, sessions store it securely on the server. Key Features of Sessions Stored on the server Identified by session ID More secure than cookies Used for authentication ma...

  Introduction Modern web application testing is incomplete without Burp Suite. It is one of the most widely used tools for analyzing, intercepting, and modifying HTTP requests. This Burp Suite Tutorial 2026 will guide you through its core features and how to use it in real-world cybersecurity and penetration testing. What is Burp Suite Burp Suite is a web security testing platform used by ethical hackers to identify vulnerabilities in web applications. It acts as a proxy between your browser and the target website, allowing you to inspect and manipulate traffic. Why Burp Suite is Important Intercept HTTP/HTTPS requests Modify requests and responses Test authentication systems Discover web vulnerabilities Installation Burp Suite is pre-installed in Kali Linux. For other systems, download it from the official website. Setting Up Burp Proxy Step 1: Open Burp Suite Launch the application and select “Temporary Project”. Step 2: Enable Intercept Go to Proxy → Intercept → Turn ON. Step ...

  Introduction After learning the basics of network scanning, the next step is mastering advanced techniques. Nmap is not just a simple scanner—it is a powerful tool capable of deep network analysis and vulnerability detection. This Nmap Advanced Guide 2026 covers practical commands used in real-world penetration testing and cybersecurity assessments. Why Advanced Nmap Matters Detect hidden services Bypass basic firewall rules Perform stealth scanning Identify vulnerabilities Prerequisites Before continuing, you should understand: Basic Nmap commands Ports and protocols Network fundamentals Advanced Nmap Commands 1. Stealth Scan (SYN Scan) nmap -sS example.com This scan is faster and less detectable than full connection scans. 2. UDP Scan nmap -sU example.com Used to detect UDP services like DNS and SNMP. 3. OS Detection nmap -O example.com Identifies the operating system of the target. 4. Aggressive Scan nmap -A example.com Combines OS detection, version detection, script scannin...

  Introduction Reconnaissance is the foundation of every successful penetration test. Before exploiting any system, security professionals must understand the target’s structure, assets, and attack surface. This Reconnaissance Workflow 2026 provides a complete step-by-step approach, combining multiple tools and techniques used in real-world cybersecurity. What is Reconnaissance Reconnaissance (Recon) is the process of gathering information about a target system before launching an attack or security assessment. It is divided into two types: Passive Recon (no direct interaction) Active Recon (direct interaction with target) Why Recon is Important Identifies attack surface Reduces guesswork Improves success rate Helps find hidden assets Complete Recon Workflow Step 1: Domain Information Gathering whois example.com Step 2: DNS Enumeration nslookup example.com dig example.com Step 3: Subdomain Discovery subfinder -d example.com Step 4: Live Host Detection nmap -sn example.com Step 5: ...

  Introduction In modern web infrastructures, organizations often use multiple third-party services like hosting platforms, CDNs, and SaaS tools. If these services are not configured properly, they can lead to a serious vulnerability known as Subdomain Takeover. This Subdomain Takeover guide 2026 explains how attackers identify misconfigured DNS records and how security professionals can prevent them. What is Subdomain Takeover Subdomain Takeover occurs when a subdomain points to an external service that is no longer active, but the DNS record still exists. An attacker can claim that external resource and gain control over the subdomain. Why It is Dangerous Full control over subdomain content Phishing attacks Cookie stealing Brand reputation damage How Subdomain Takeover Works A subdomain (e.g., test.example.com) points to a service (e.g., GitHub Pages) The service is deleted or inactive DNS record still exists Attacker registers the same service Attacker gains control of the subd...

  Introduction After learning tools like Nslookup and Dig, the next step in cybersecurity reconnaissance is DNS Enumeration. This process helps security professionals gather detailed information about a target domain. This DNS Enumeration guide 2026 explains how to collect domain data using multiple tools and techniques in a structured way. What is DNS Enumeration DNS Enumeration is the process of collecting DNS-related information about a target domain, including subdomains, name servers, mail servers, and IP addresses. It plays a critical role in reconnaissance , penetration testing , and bug bounty hunting . Why DNS Enumeration is Important Discover hidden subdomains Identify attack surface Gather infrastructure details Support vulnerability discovery Basic DNS Enumeration Workflow Domain identification DNS record lookup Subdomain discovery IP mapping Data analysis Step 1: Basic DNS Lookup nslookup example.com Step 2: Advanced DNS Query dig example.com Step 3: Whois Information...

  Introduction In cybersecurity and network analysis, understanding DNS is essential. While Nslookup is useful for basic queries, professionals prefer Dig for more detailed and flexible DNS analysis. This Dig tutorial 2026 will help you learn how to perform advanced DNS queries for reconnaissance , troubleshooting , and penetration testing . What is Dig Dig (Domain Information Groper) is a command-line tool used to query DNS servers and retrieve detailed DNS records. It provides more control and detailed output compared to basic DNS tools, making it popular in cybersecurity tools and network analysis . Why Use Dig Perform advanced DNS queries Get detailed DNS response data Troubleshoot domain issues Support reconnaissance in ethical hacking Installation On Kali Linux: sudo apt install dnsutils Basic Syntax dig domain.com This returns detailed DNS information including headers and answer sections. Common Dig Commands 1. Basic DNS Lookup dig example.com 2. Query Specific Record (A ...

  Introduction Understanding how domain names translate into IP addresses is a fundamental concept in networking and cybersecurity. Nslookup is a simple yet powerful command-line tool that helps users query DNS records and troubleshoot network issues. This guide provides a step-by-step explanation of Nslookup with practical examples, making it ideal for beginners in cybersecurity and network analysis. What is Nslookup Nslookup (Name Server Lookup) is a command-line utility used to query Domain Name System (DNS) servers. It helps retrieve information such as IP addresses, domain records, and mail server details. Nslookup is commonly used in network troubleshooting , cybersecurity analysis , and penetration testing reconnaissance . Why Use Nslookup Resolve domain names to IP addresses Query DNS records (A, MX, NS, TXT) Diagnose DNS-related issues Perform basic reconnaissance Basic Syntax nslookup domain.com This command returns the IP address of the target domain. Common Nslookup Com...

  Introduction Web security testing is an essential part of cybersecurity, and automated tools play a key role in identifying vulnerabilities quickly. Nikto is one of the most effective open-source tools used for scanning web servers and detecting security issues. This guide explains how to use Nikto step by step, making it ideal for beginners in penetration testing and ethical hacking. What is Nikto Nikto is an open-source web server scanner designed to detect vulnerabilities, outdated software, and misconfigurations. It performs comprehensive tests against web servers and identifies potential security risks. Nikto is widely used in penetration testing tools and vulnerability scanning processes. Why Use Nikto Detect outdated server software Identify common vulnerabilities Find misconfigurations in web servers Perform automated web security scanning Installation Install Nikto on Kali Linux: sudo apt install nikto Check version: nikto -Version Basic Nikto Commands 1. Scan a Websit...

   Abstract Password-based authentication remains one of the most widely used security mechanisms in modern computing systems. Despite the availability of advanced authentication methods, weak password practices continue to expose systems to significant risks. This article provides an academic overview of password security, common vulnerabilities, and effective mitigation strategies in contemporary cybersecurity environments. Introduction In the digital era, authentication plays a central role in protecting sensitive information. Passwords are often the first and sometimes the only line of defense. However, human behavior, such as choosing weak or reused passwords, significantly reduces their effectiveness. As a result, attackers frequently target password-based systems to gain unauthorized access. Fundamentals of Password Security A secure password system relies on three main principles: Complexity : Use of uppercase, lowercase, numbers, and symbols Length : Longer passwords ...

Introduction Password security remains one of the weakest points in modern systems. Even today, many breaches happen because of weak or reused passwords. Security professionals use tools like John the Ripper to test password strength and identify vulnerabilities before attackers can exploit them. What is John the Ripper John the Ripper is a popular open-source password auditing and recovery tool. It works by taking hashed passwords and attempting to recover the original plaintext passwords using different attack methods. It supports multiple platforms including Linux, Windows, and macOS, and is widely used in penetration testing and security assessments. Why John the Ripper is Important Helps identify weak passwords Supports many hash types such as MD5, SHA, and NTLM Useful for penetration testing and security audits Improves overall authentication security How John the Ripper Works John the Ripper follows a simple process. It takes password hashes as input, generates possible password...

  Overview Password security remains one of the most critical aspects of cybersecurity. When weak passwords are used, attackers can exploit them using advanced cracking tools. Hashcat is one of the most powerful tools designed for this purpose. What is Hashcat? Hashcat is an advanced password recovery tool that uses GPU acceleration to crack hashes at high speed. It supports a wide range of hashing algorithms and attack modes. Why Hashcat is Important Hashcat is widely used because: Extremely fast performance using GPU Supports multiple attack methods Works with hundreds of hash types Highly customizable Installation On Kali Linux: sudo apt install hashcat Basic Usage Example command: hashcat -m 0 -a 0 hash.txt wordlist.txt Command Breakdown -m 0 → Hash type (MD5) -a 0 → Dictionary attack hash.txt → Target hash file wordlist.txt → Password list Attack Modes Dictionary Attack Uses a predefined list of passwords. Brute Force Attack Tries all possible combinations. Hybrid Attack Combi...

  Overview Before attempting to crack a hash, you must first identify its type. Different algorithms such as MD5, SHA-1, and bcrypt require different cracking approaches. Hash identification tools help you determine the most likely algorithm quickly and accurately. hashid is a simple and effective utility used to identify hash types based on patterns and characteristics. What is hashid? hashid is a lightweight command-line tool that analyzes a given hash string and suggests possible hashing algorithms. It compares the structure and length of the hash with known signatures. Why Hash Identification Matters Correct identification is essential because: Each algorithm requires a different cracking mode Choosing the wrong type wastes time and resources Accurate detection improves success rate Installation On Kali Linux: sudo apt install hashid Basic Usage Identify a hash: hashid 5f4dcc3b5aa765d61d8327deb882cf99 Sample Output The tool may return multiple possible matches such as: MD5 NTLM...

Overview In modern penetration testing, speed and accuracy are critical. Security researchers need tools that can quickly identify vulnerabilities across multiple targets without missing important issues. Nuclei is a powerful solution designed for automated vulnerability scanning using customizable templates. What is Nuclei? Nuclei is an open-source vulnerability scanner developed by ProjectDiscovery. It works by sending requests to a target and matching responses against predefined templates to detect security issues. Unlike traditional scanners, Nuclei is lightweight, flexible, and highly customizable. Why Nuclei is Important Nuclei has become widely used because it offers: Fast scanning performance Template-based detection Support for multiple protocols such as HTTP, DNS, and TCP Easy integration into automation workflows How Nuclei Works Nuclei operates using templates written in YAML format. Each template defines: The request to send The pattern to match The severity level The pro...

In today's interconnected world, information is the most valuable asset. Cryptography is the science that ensures this information remains private, authentic, and untampered with. This guide covers everything from fundamental principles to modern-day applications. 1. What is Cryptography? Cryptography (from the Greek words kryptos meaning hidden and graphein meaning writing) is the practice of securing communication through mathematical techniques. The main goal is to convert Plaintext (readable information) into Ciphertext (unreadable scrambled data) so that only those with the correct "key" can read it. 2. The Core Pillars (CIA Triad + 1) Cryptography serves four primary functions: Confidentiality: Only the intended recipient can read the message. Integrity: The message cannot be altered during transit without being detected. Authentication: Proving the identity of the sender. Non-repudiation: The sender cannot deny having sent the message later. 3. Types of Cr...

  Welcome to another segment of our Information Gathering series! In our previous post, we explored WhatWeb to identify a website's internal technology stack. However, to understand who is behind a website, when it was registered, or which company manages its infrastructure, we need a technique called WHOIS Lookup . WHOIS is a fundamental footprinting method used by penetration testers to gather domain-level intelligence. What is WHOIS? WHOIS (pronounced as the phrase "who is") is a query and response protocol used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name or an IP address block. Essentially, it acts as a public directory providing details about domain ownership, registration dates, expiry dates, and authoritative name servers. Why is it Important for Ethical Hackers? For a security researcher, a WHOIS lookup is vital for several reasons: Ownership Identity: Identifies the person or organization ...

  Welcome back to CyberShield! Amra ager post-e Nmap diye network scanning shikhechi. Kintu jokhon apnar target ekti website hoy, tokhon shudhu port scan korle hoy na; apnake jante hoy shei site-ti kon technology diye toiri. Ajke amra ekti powerful reconnaissance tool niye alochona korbo, jar nam holo WhatWeb . WhatWeb Ki? WhatWeb holo ekti open-source "Next-generation web scanner." Eti ekti website-er technology stack identify korte babohar kora hoy. Mane, ekti site kon CMS (Content Management System), kon web server, kon programming language, ebong kon kon plugin babohar korche, ta WhatWeb ekti command-er maddhome bole dite pare. WhatWeb Keno Babohar Korben? Passive Reconnaissance-er khetre WhatWeb khub-i guruttopurno. Eti diye niche-r jinish gulo khuje paoa jay: CMS Discovery: Site-ti ki WordPress, Joomla, naki Drupal? Web Server Information: Server-ti ki Apache, Nginx, naki Microsoft-IIS? Frameworks: Site-ti ki React, Vue.js, naki Laravel babohar korche? Plugins ...

  Welcome back to CyberShield! We have spent a lot of time discussing technical vulnerabilities like SQL Injection and Directory Traversal. However, today we are going to talk about a method that doesn't target software—it targets the Human Mind . Welcome to the world of Social Engineering . What is Social Engineering? Social Engineering is the psychological manipulation of people into performing actions or divulging confidential information. In the world of cybersecurity, it is often called "Human Hacking." No matter how strong your firewall is, if an employee gives away their password to a stranger, the system is compromised. Why Social Engineering is Dangerous Hard to Patch: You can patch software, but you cannot "patch" human emotions like curiosity, fear, or trust. Low Technical Requirement: An attacker doesn't need to be a master coder to trick someone over the phone. The Weakest Link: Humans are often considered the weakest link in any security ch...

Welcome back to CyberShield! Search engines are more powerful than most people realize. Beyond regular queries, they can reveal deeply indexed content that is not easily visible through normal browsing. In cybersecurity, this technique is known as Google Dorking . It allows researchers to uncover publicly exposed data using advanced search queries without ever directly interacting with the target's server. What is Google Dorking? Google Dorking refers to the use of advanced search operators to locate specific types of information within search engine indexes. Instead of performing simple keyword searches, users apply structured queries to filter results and uncover hidden or sensitive data that was never meant to be public. Why It Matters in Security Testing For penetration testers and bug bounty hunters, this technique is a vital part of passive reconnaissance . It helps to: Identify exposed files and directories: Finding folders that should be private. Discover forgotten or unl...

  Welcome back to CyberShield! We have explored web vulnerabilities and reconnaissance. Now, it's time to go deeper into the network layer. If you want to see exactly what is traveling through your Wi-Fi or Ethernet cables, you need to master Wireshark . What is Wireshark? Wireshark is the world’s most popular network protocol analyzer. It allows you to capture and interactively browse the traffic running on a computer network. Think of it as a "microscope" for your network—it lets you see every single packet that is sent or received. Why Do Pentesters Use Wireshark? For a Cybersecurity professional, Wireshark is essential for: Analyzing Protocols: Understanding how HTTP, DNS, TCP, and TLS work. Finding Vulnerabilities: Spotting unencrypted sensitive data (like passwords) sent over plain HTTP or FTP. Incident Response: Investigating how a malware or virus is communicating with its Command and Control (C2) server. Network Troubleshooting: Fixing latency or connection ...