Short answer: To become an ethical hacker, first learn networking, Linux and Windows, and one scripting language such as Python. Then study how attacks work, using the OWASP Top 10 for web applications and MITRE ATT&CK for attacker techniques. Practise only in legal labs and capture-the-flag (CTF) challenges. Document what you find, and add a recognised certification such as CEH, CompTIA PenTest+ or OSCP when you are ready. Most people start in a security operations or junior security role before moving into full penetration testing.
This guide focuses on the offensive side of security: penetration testing and ethical hacking. If you are still choosing between security careers, read how to start a career in cyber security first. It compares SOC, GRC, cloud security and other paths.
What an ethical hacker actually does
An ethical hacker is hired to find weaknesses in systems before criminals do, with the owner’s written permission. A typical engagement follows the same stages each time.
- ScopeWritten permission and rules
- ReconMap the target
- ScanFind weaknesses
- ExploitProve the risk safely
- ReportExplain and recommend fixes
Permission is not optional. In India, accessing a computer system without the owner’s permission can make you liable to pay compensation under Section 43 of the Information Technology Act, 2000, and it becomes a criminal offence under Section 66 if it is done dishonestly or fraudulently. Good intentions are not a defence for testing without permission. Practise only on systems you own, on intentionally vulnerable labs, or on bug bounty programmes that explicitly invite testing.
The step-by-step path
- Networking. Learn TCP/IP, ports, DNS, HTTP and HTTPS, and routing. You cannot attack or defend what you do not understand. Tools: Wireshark, tcpdump.
- Operating systems. Get comfortable on the Linux command line and learn how Windows users, services and permissions work. Tools: Kali Linux, PowerShell.
- Scripting. Learn enough Python or Bash to automate repetitive tasks and read other people’s exploit code.
- Web application security. Study the OWASP Top 10, including injection, broken access control and security misconfiguration, and practise finding them. Tools: Burp Suite, OWASP ZAP.
- Scanning and exploitation. Learn how scanners find weaknesses and how exploitation frameworks prove them. Tools: Nmap, Nessus or OpenVAS, Metasploit.
- Attacker techniques. Use MITRE ATT&CK to understand how real attackers move after they get in, and how defenders detect them.
- Cloud basics. More and more targets run on AWS and Azure, so learn how identity, storage and network permissions work in the cloud.
- Reporting. Practise writing clear findings: what you found, how serious it is, how you proved it and how to fix it.
Certifications compared
Certifications help you get past resume filters, but employers still test practical skills in interviews. Check each provider’s website for current fees, exam formats and renewal rules before you book.
| Certification | Provider | Format | Good for |
|---|---|---|---|
| Certified Ethical Hacker (CEH), currently version 13 | EC-Council | Knowledge exam of 125 multiple-choice questions in 4 hours, plus an optional 6-hour practical exam | Broad coverage of attack techniques, and widely listed in job posts |
| CompTIA PenTest+ | CompTIA | Vendor-neutral exam. Valid for 3 years and renewed through CompTIA’s continuing education programme | A structured introduction to penetration testing |
| OSCP / OSCP+ | OffSec | Hands-on exam. Since 1 November 2024, passing earns OSCP+, which is valid for 3 years, as well as the lifetime OSCP | Proving practical exploitation skills. Harder, and usually taken after some experience |
A sensible order for most beginners is fundamentals first, then CEH or PenTest+, then OSCP once you are comfortable in labs.
To see how these certifications line up with the modules in the cyber security syllabus, read ASTI’s module-by-module guide.
Building proof without a job
- Lab write-ups. Document machines you solve in legal practice labs, explaining your method and not just the answers.
- CTF results. Take part in capture-the-flag competitions and write up the challenges you solved.
- A home lab. Set up vulnerable virtual machines, attack them, then fix them and explain the fix.
- Responsible disclosure. If you join a bug bounty programme, follow its rules exactly. Rewards are not guaranteed, but a well-written report shows employers your skill.
Common mistakes
- Jumping straight to hacking tools without learning networking first
- Testing a college, employer or public website “just to see”, which is illegal without permission
- Collecting certificates without hands-on practice
- Ignoring report writing, which is the part clients actually read
Learning ethical hacking at ASTI
The ASTI Cyber Security course has 13 modules, from security fundamentals and network and application security to a dedicated ethical hacking and penetration testing module, cloud security and a capstone project. About 70% of the sessions are practical, using tools such as Nmap, Wireshark, Burp Suite, Metasploit and SIEM platforms. You can learn in the BTM 1st Stage classroom or live online. Placement assistance does not guarantee a job.
Frequently asked questions
Can I become an ethical hacker without a degree?
Some employers ask for a degree and some do not. Practical skill, lab experience and a recognised certification can open doors, but check the requirements in the job posts you are targeting.
How long does it take to become an ethical hacker?
It depends on your starting point and how much you practise. Learning the fundamentals usually takes several months of steady study. Job-ready penetration testing skills take longer and grow with hands-on experience.
Is CEH or OSCP better?
They test different things. CEH covers a broad body of knowledge and appears in many job listings. OSCP is a hands-on exam that proves you can exploit systems. Many people take CEH or PenTest+ first and OSCP later.
Is ethical hacking legal in India?
Yes, when you have the system owner’s written permission and stay within the agreed scope. Without permission, accessing a system can lead to liability under Section 43 of the Information Technology Act, 2000, and to criminal charges under Section 66 if done dishonestly or fraudulently.
Do I need to know programming?
You need scripting more than full software development. Python and Bash are enough to automate tasks and understand exploit code.