How to Pass Technical Screening Interviews for Certified Ethical Hacker (CEH)
A complete step-by-step masterclass on passing CEH v13 technical screening interviews, ethical hacking methodologies, Nmap scanning, Metasploit exploitation, and web application attacks.
Summary: Master EC-Council CEH v13 penetration testing methodology, Nmap scanning flags, Metasploit system hacking, SQL Injection, Cross-Site Scripting (XSS), and WPA2/WPA3 Wi-Fi security for CEH interviews.
1. CEH v13 Exam & Penetration Tester Screening Scope
The Certified Ethical Hacker (CEH v13) by EC-Council validates knowledge of offensive security tools, attack vectors, and ethical hacking methodology. 1. **Information Security & Ethical Hacking Overview (6%):** Cyber Kill Chain, MITRE ATT&CK framework, Hacker types, Security controls. 2. **Reconnaissance & Footprinting (7%):** OSINT, Search Engine Hacking, DNS footprinting, Whois lookup, Social engineering reconnaissance. 3. **Scanning & Enumeration (21%):** Nmap, Hping3, Port scanning, Banner grabbing, NetBIOS/SMB/SNMP/LDAP enumeration. 4. **System Hacking (17%):** Password cracking, Privilege escalation, Steganography, Clearing logs. 5. **Network & Perimeter Hacking (17%):** Sniffing (Wireshark), DoS/DDoS, Session Hijacking, Evading IDS/Firewalls/Honeypots. 6. **Web Application & Database Hacking (16%):** OWASP Top 10, Web server attacks, SQL Injection, XSS, CSRF, Parameter tampering. 7. **Cloud, Wireless & IoT Hacking (16%):** WPA2/WPA3 cracking, Cloud security threats, IoT/OT vulnerabilities, Cryptography.
2. Nmap TCP Scanning & OS Fingerprinting Techniques
**Interview Scenario:** *"Explain the technical difference between an Nmap SYN Stealth Scan (`-sS`) and a TCP Connect Scan (`-sT`)."* * **SYN Stealth Scan (`-sS` - Half-Open Scan):** Sends a TCP SYN packet. If target responds with `SYN/ACK`, port is OPEN. Nmap immediately sends a `RST` (Reset) packet to tear down the connection without completing the 3-Way Handshake. Requires root privileges; avoids logging on legacy application servers. * **TCP Connect Scan (`-sT` - Full Open Scan):** Completes the full 3-Way Handshake (`SYN -> SYN/ACK -> ACK`) using OS system calls. Used when running without root privileges. Easily logged by target firewalls. * **OS Fingerprinting (`-O`):** Analyzes TCP window size, initial sequence numbers (ISN), and ICMP error responses against Nmap's OS signature database.
3. System Hacking Phase & Metasploit Framework
**Interview Scenario:** *"Walk me through the 5 phases of System Hacking and explain how Metasploit Meterpreter payloads maintain stealth."* 1. **Gaining Access:** Exploiting service vulnerabilities to launch shell code. 2. **Escalating Privileges:** Elevating low-privilege access to SYSTEM / Root. 3. **Executing Applications:** Running trojans, keyloggers, or pivot proxies. 4. **Hiding Files:** Using Steganography or NTFS Alternate Data Streams (ADS). 5. **Clearing Logs:** Deleting audit trails in Windows Event Viewer or Linux `/var/log/`. * **Metasploit Meterpreter Payload:** Resides 100% in system RAM memory (injected into target process like `lsass.exe` or `explorer.exe`) without writing files to disk, evading traditional signature-based antivirus detection.
4. Web Application Attacks: SQL Injection & XSS
**Interview Scenario:** *"Differentiate between Reflected XSS, Stored XSS, and Blind SQL Injection."* * **Reflected XSS:** Malicious script payload is contained in HTTP request URL parameters and reflected immediately in the server response page (not stored in DB). * **Stored XSS:** Malicious script is saved persistently in a database (e.g. comment section, user profile bio) and executed in the browser of any user viewing the page. * **Blind SQL Injection:** The web application does not output database errors or data on screen. Attacker infers data character-by-character using **Boolean-based** (true/false page responses) or **Time-based** (`WAITFOR DELAY '0:0:5'`) queries.
5. Wireless Network Security & WPA2/WPA3 Cracking
**Interview Scenario:** *"How is a WPA2 4-Way Handshake captured and cracked using the Aircrack-ng suite?"* 1. **Monitor Mode:** Put wireless interface into monitor mode (`airmon-ng start wlan0`). 2. **Packet Capture:** Target specific AP BSSID and channel (`airodump-ng -c 6 --bssid 00:11:22:33:44:55 -w capture wlan0mon`). 3. **Deauthentication Attack:** Send deauth frames to force a connected client to reconnect (`aireplay-ng -0 5 -a BSSID -c CLIENT_MAC wlan0mon`). 4. **Offline Hash Cracking:** Crack captured 4-Way Handshake offline using Hashcat or Aircrack-ng against a dictionary wordlist: `aircrack-ng -w wordlist.txt -b BSSID capture.cap`