Computer Security

A collection of security research and practical exercises covering six core areas of computer security — from cryptographic implementations to malware analysis — using industry-standard tools and methodologies.

Overview

This repository documents hands-on work across offensive and defensive security domains, including vulnerability exploitation, network defense, and forensic analysis. Each module contains detailed methodology documentation, tool configurations, and findings.

Modules

Module	Focus Area	Key Tools
Encryption and Cryptography	AES/RSA implementation, digital signatures, custom Python encryption client	OpenSSL, Python cryptography
Linux Security and Social Engineering	CLI security challenges, browser exploitation, phishing attack vectors	OverTheWire Bandit, BeEF Framework
Password Security Analysis	Offline hash cracking, online brute-force, dictionary attacks	John the Ripper, Hydra, rockyou.txt
Penetration Testing	Network reconnaissance, CVE exploitation, reverse shells	Nmap, Metasploit Framework
Malware Analysis and Intrusion Detection	Static analysis, YARA rule development, Snort IDS deployment	YARA, Snort 3, exiftool, binwalk
Web Application Security	XSS (stored/reflected/upload), CSRF exploitation and defense	Google Gruyere, custom payloads

Tech Stack

Offensive Tools: Metasploit, Nmap, Hydra, John the Ripper, BeEF, Burp Suite

Defensive Tools: Snort IDS, YARA, OpenSSL

Analysis Tools: exiftool, binwalk, strings, sha256sum

Languages: Python, Bash, HTML/JavaScript

Environment: Kali Linux, Metasploitable3

Highlights

• Real malware analysis — analyzed an AgentTesla infostealer sample from MalwareBazaar, including metadata forensics and custom YARA detection rules
• CVE exploitation — demonstrated exploitation of CVE-2015-3306 (ProFTPD mod_copy) and CVE-2010-2075 (UnrealIRCd backdoor) with full attack chain documentation
• Custom tooling — built a Python AES-256-CBC encryption client from scratch using the cryptography library's hazmat primitives
• IDS rule development — deployed Snort 3 with custom detection rules, including analysis of HTTPS limitations on signature-based detection
• Web attack vectors — demonstrated 4 distinct attack types (File Upload XSS, Reflected XSS, Stored XSS, CSRF) with root cause analysis and countermeasures

Project Structure

Computer-Security/
├── encryption-and-cryptography/
│   ├── files/
│   │   ├── encrypt.py                  # Custom AES-256-CBC encryption client
│   │   ├── plaintext.txt               # Sample plaintext input
│   │   ├── encrypted_file.enc          # AES-encrypted output
│   │   ├── decrypted_file.txt          # Decrypted verification
│   │   ├── symmetric_key.key           # AES symmetric key
│   │   ├── public_key.pem              # RSA public key
│   │   ├── private_key.pem             # RSA private key
│   │   ├── rsa_encrypted.enc           # RSA-encrypted data
│   │   ├── rsa_decrypted.txt           # RSA-decrypted output
│   │   ├── signature.bin               # Digital signature
│   │   └── output.txt                  # Execution output
│   ├── README.md
│   ├── Solutions.pdf
│   └── Task.pdf
├── linux-security-and-social-engineering/
│   ├── README.md, Solutions.pdf, Task.pdf
├── password-security-analysis/
│   ├── README.md, Solutions.pdf, Task.pdf
├── penetration-testing/
│   ├── README.md, Solutions.pdf, Task.pdf
├── malware-analysis-and-ids/
│   ├── README.md, Solutions.pdf, Task.pdf
├── web-application-security/
│   ├── README.md, Solutions.pdf, Task.pdf
└── README.md

Disclaimer

All security testing was performed in controlled, authorized environments (local VMs, intentionally vulnerable applications). This repository is for educational and portfolio purposes only.