CyberShield

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 ...

  Introduction In penetration testing and cybersecurity, the first step is always reconnaissance. Before identifying vulnerabilities, you need to understand the target system—what services are running, which ports are open, and what technologies are in use. One of the most powerful tools for this purpose is Nmap (Network Mapper). What is Nmap? Nmap is an open-source network scanning tool used to discover hosts and services on a network. Security professionals use Nmap to: Identify active devices Detect open ports Discover running services Gather system information Why Nmap is Important Nmap plays a crucial role in the reconnaissance phase: Network Discovery It helps identify which systems are online. Port Scanning You can find open, closed, and filtered ports. Service Detection Nmap can detect the version of services running on ports. Security Assessment It helps identify potential entry points for attackers. Installing Nmap On Kali Linux: sudo apt install nmap Basic Nmap Commands ...