We may earn an affiliate commission when you visit our partners.
Course image
Bryson Payne

Join more than 70,000 students learning coding and hacking from Dr. Bryson Payne, and 12,000+ students in his top-rated, hands-on Ethical Hacking + Cybersecurity course.  

Read more

Join more than 70,000 students learning coding and hacking from Dr. Bryson Payne, and 12,000+ students in his top-rated, hands-on Ethical Hacking + Cybersecurity course.  

New and updated for VirtualBox 6.1 and Kali 2022 and later. Learn Ethical Hacking, one of the fastest-growing and highest-paying careers, with over 1 Million cybersecurity job openings available this year.  Learn practical, useful cybersecurity step-by-step from Computer Science Professor Dr. Bryson Payne, a SANS|GIAC Certified Pen Tester (GPEN), Certified Ethical Hacker (CEH) and Certified Information Systems Security Professional (CISSP), and author of the Amazon #1 New Release and Top 10 Best Seller, Teach Your Kids to Code (2015, No Starch Press) and his latest book, Go H*ck Yourself  (2022, No Starch Press). Dr. Payne is also the Coordinator for Cyber Program and the founding Director of the Center for Cyber Operations Education at the University of North Georgia and directs the UNG National Cyber Warrior Academy summer program. He served as a member of the Coaching staff for the US Cyber Team in the first-ever International Cybersecurity Competition in Athens, Greece in 2022 and continues to serve as a Senior Tech Mentor for Reverse Engineering for the 2022-2023 team.

Update 2022: Just added a new lesson in Section 5 on Social Engineering/Phishing, and...Order Dr. Payne's new book, "Go H*ck Yourself" on Amazon or at No Starch Press now.

Give Yourself a Huge Advantage in a High-Tech World

  • Quickly master new hands-on skills in Linux, Windows and Android hacking and cybersecurity.

  • Set up your own safe, FREE virtual network and VM (virtual machine) lab for Ethical Hacking on your PC, Mac, and Linux.

  • Protect yourself from viruses, phishing, ransomware, and other attacks by learning how the bad guys work, and how to stop them.

  • Includes Mobile Hacking on your own Android VM, plus Car Hacking using can-utils and ICSim on Kali Linux.

  • Great for beginners, or for capable computer users who want to learn both how and why to secure their data.

  • Learn to fix vulnerabilities, and how to stop 85% of attacks by doing just four things. 

This is the security course everyone should take.

Packed with real-world, practical examples, real hacking techniques, and easy-to-follow plain English instruction, Real-World Ethical Hacking is the course for the new generation of cyber heroes, as they build one of the top job skills of the 21st century. With over S. this year alone, and over 6 Million openings expected worldwide over the next few years, now is the time to skill up in cyber.  

I designed this course to be easily understood by beginners, with examples I use in my college information security courses and in high-school cyber summer camps. Whether you're retooling for a career change, adding skills to your resume for a raise, or just getting started, Real-World Ethical Hacking is the course for you.

Quick, 4- to 10-minute lessons will get you performing real ethical hacking exercises in minutes. Over 75 video lectures and more than 10hours of content will give you the practice you need to develop powerful new skills in cybersecurity and penetration testing. Protect your identity, your computer, your information, and your life - avoid social engineering, phishing, online attacks, ransomware and more. Plus, practical skills like:

  • Retrieve files from an old computer (Mac or PC, laptop or desktop), even if you've forgotten the password

  • Set up a virtual "sandbox" to safely open suspicious files without exposing your "real" computer

  • Learn command-line short-cuts and power tools that make you look like a computer wizard.

  • Understand how viruses and backdoors infect your computer AND phone, and how to stop them.

Everything you need to get started right away

Complete with all FREE online resources (VirtualBox, Kali Linux, and You'll also receive a Certificate of Completion upon finishing the course.

No Risk: Preview videos from Sections 1, 2, and 4 now for FREE, and enjoy a 30-day money-back guarantee when you enroll - zero risk, unlimited payoff. And, we've made this course easy to afford so anyone can get started now.

Sign up for this course and get started securing yourself, your family, and your business today.

New section on Car Hacking shows how to perform a Replay Attack on your car's Controller Area Network (CAN) using a $20-$70 cable and Kali Linux running CANsniffer and CANplayer.  

Praise for Dr. Payne's courses on Udemy:

"Inspired" - ...An inspiring course taught by an inspired teacher. The examples are well-chosen demonstrating principles through engaging, colorful projects rather than by teaching abstract principles first... — Kent Osband, Udemy student

Clear examples... Bryson's delivery is well paced and good fun. — Sean Jon Darcy, Udemy student

"Dr. Bryson Payne is a computer scientist and professor of the highest caliber... he brings the power of computers within easy reach for learners young and old."—Dr. Antonio Sanz Montemayor, Informatics Professor, Universidad Rey Juan Carlos, Spain

Enroll now

Here's a deal for you

We found an offer that may be relevant to this course.
Save money when you learn. All coupon codes, vouchers, and discounts are applied automatically unless otherwise noted.

What's inside

Learning objectives

  • Secure your computer, your network, and your data from 99% of all attacks on the internet.
  • Test for security vulnerabilities using the tricks the bad guys use.
  • Find and fix weaknesses and harden your computer's security.
  • Avoid phishing, viruses, ransomware, and online scams.
  • Keep yourself safe online, at home, at school, or at work.

Syllabus

By the end of this section, you'll be able to reset any user's password and create an administrator account on almost any Windows PC using just 2 reboots, 2 special keys, and 4 terminal commands!
Read more

Real-World Ethical Hacking is based on lessons taught in the National Cyber Warrior Academy, but this video course is not endorsed or sponsored by the University or by the NSA. All opinions expressed are the author's alone, and even ethical hacking carries some risk. Please use the tools and techniques in this course responsibly and ONLY on computers you own or have express, written permission to test.

Overview: What is Ethical Hacking?

Our first hands-on, real-world ethical hacking exercise: Hacking Windows, resetting a password and creating new admin users, using a boot disk.

The attack vector for this hack will be the Windows "Sticky Keys" app SETHC.EXE, triggered any time you press the SHIFT key 5 times in Windows.

Where to get a legal copy of Windows 10 Enterprise, and how to burn your own Windows 10 install/boot disc.


Just two reboots, two special keys, and four commands to PWN any Windows PC. 

Second reboot, second key combo, and final two commands to add an admin/root/super user to any Windows box from Windows XP to Windows 10.1!

Stage 3: Gaining Access! Log in as root/super/admin user and recover your files!

Lessons Learned:

  • Physical access is total access
  • Never leave your laptop/desktop unattended
  • Ethical Hacking is practical and useful!

To protect against this hack: 

  1. Change your BIOS settings to require a password to change the boot order or boot device
  2. Encrypt your files to make them unreadable without your ORIGINAL password
Extra: Mac Root Hack!
Use VirtualBox to create your own FREE, legal, Ethical Hacking lab with Windows, Linux, and Android VM's (virtual machines)!

Updated for VirtualBox 6.1 and newer - get started building your FREE ethical hacking virtual lab with Oracle VirtualBox on Mac, Windows, or Linux.

Updated for Kali Linux 2020.2 and newer versions!

Create a Windows 10 VM
Create an Android Phone/Tablet VM for Mobile Hacking!
The Ultimately Hackable Metasploitable!
Troubleshooting VirtualBox on Mac/Windows (Updated 6/2020 for VirtualBox 6.1)
Create and manipulate files from the command line in Linux and Windows, get to know your environment variables, check network settings and more!
Intro to Command-Line Linux and Windows
Basic Linux Commands
Command-Line Linux File Magic!
More Helpful Linux Commands

Display output like a table (| column –t):
mount | column –t
cat /etc/passwd | column -t -s :

Go back to previous directory: cd -

Turn on aliases in your .bashrc alias ll=‘ls -l’; alias la=‘ls -a’

Run multiple commands: ; (in order) or && (if successful)

Reuse last argument: !$ Reuse last command: !! (e.g. sudo !!)

Reverse text (rev): echo hello | rev

Draw banner letters (figlet): figlet hello

clear [also ctrl+L]

cal [calendar] factor 24 [factors…] > filename [empty file]

head [top of file] tail [last few lines] grep [superfind]

Basic Command-Line Commands for Windows
Windows File Commands
Advanced Windows Command-Line Commands
Command-Line Review for Linux and Windows
Create two VirtualBox networks, one private and the other public, and learn to switch your virtual machines from one network to the other, and when you should use each one.
Virtual Networking in VirtualBox
Creating the Private, Host-Only 10.0.3.x Network
Connecting Your VMs to the Host-Only Network
Creating and Using a Public NAT Network in VBox
Updating Kali and Windows VMs
Build a perfect Spear-Phishing email, and understand how to protect against phishing at work and at home.
Intro to Social Engineering
The Social Engineer's Toolkit in Kali Linux
Cloning Facebook and Harvesting User Passwords

2022 Update: If you're having trouble cloning a site in the previous lesson, try the Web Site Templates option in SET (press 1, 2, 3, 1, then choose any of the three pre-made web site templates, I chose Twitter). SET provides three usable templates to show how easy it is to trick users into filling in their username and password in a phishing site.

Intro to Spear-Phishing
Advanced IP Address Masking: Hiding Your Real URL
Crafting the Perfect Spear-Phishing Email
Capturing the User's Login and Password in Kali

A quick review and bonus on cloning Twitter's login page, updated for Kali 2020.2 and later.

Review: Social Engineering Techniques
Stopping Phishing at Work and at Home
Perform OSINT (open-source intelligence) information gathering about an organization or individual; use theHarvester, Recon-ng, nmap, and Legion to search, scan and enumerate devices and accounts
Information Gathering: Passive vs. Active Reconnaissance
OSINT (Open-Source INTelligence) Framework: Domain Dossier
theHarvester: How hackers find users and email information for phishing
Recon-ng: Enumeration of servers/hosts with Recon-ng
nmap: Active Scanning with nmap
Legion: Active network and vulnerability scanning with LEGION GUI
In this section, you'll learn how hackers build viruses and other malware, and how they can infect your computer to take full control of a Windows 10 machine.
Hacking Win10: The Attack Phase
Intro to Metasploit: The Hacker's Swiss Army Knife

See how easily attackers can create malware to take over your computer - you'll never want to click on a suspicious file again!

In this lesson, you learn to run the Apache web server on Kali to share your virus as a downloadable file to Windows 10.

We'll add USB support, attach a WebCam to the Win10 VM, and temporarily turn off the Windows Firewall and Virus Protection to make it a little easier for our first virus to infect the Windows 10 VM.

Infecting Your Windows 10 VM with the Virus
Use Meterpreter to download files from Windows 10, grab a screenshot of the user's desktop, listen to their keystrokes, even shut down their computer!
Attack Phase Recap/Reconnecting in Meterpreter
Intro to Meterpreter: Your Remote Attack Shell!
Viewing, Downloading and Uploading Files with Meterpreter
Stealing Screenshots, Keystrokes, and ,Webcams
How Attackers Steal Windows 10 Passwords: Privilege Escalation
Defending Yourself from Malware Attacks
Use the OpenGarages.org tools to access, test, and even modify your automobiles CAN controller area network! Includes a bonus Replay Attack!
Intro to Car Hacking!
Update: Installing can-utils and ICSim on Kali 2020 and newer
Running the Car Dashboard Simulator ICSim
Capturing CAN Traffic with CanSniffer
The Replay Attack: Replaying CAN Packets with CANplayer
Car Hacking Review

2022 Updated step-by-step instructions for reverse-engineering each function in your car by interacting with the CAN bus, finding the CAN bus IDs of the system you're changing, then determining the data values for that function and resending them one-by-one using the cansend command. A full start-to-finish tour of car hacking in 30 minutes or less!

If you're having trouble running the CAN tools, ICSim, cansniffer, etc., it could be because of video scaling on larger monitors. Be sure to change your View>Virtual Screen 1>Scaling to 100% (unscaled output) to fix VirtualBox's performance issues on high-resolution monitors. Then, you should be able to resize text inside the VM, as well as use your Magnifier tool in Windows or Zoom accessibility tool in MacOS, to be able to view your VM well without the extreme lagging that Video Scaling causes in VirtualBox. Search "VirtualBox VM slowness" in Google to find the most up-to-date fixes. My performance was more than 4x faster after fixing the scaling issue!

Special Lecture: Hacking the Car Hacking Software, to 1000 mph!
Car Hacking LIVE on Dr. Payne's VW Jetta: Facebook Live Video from NCWA 2017
Use Metasploit and Meterpreter to compromise Win7 computers from Kali Linux using common vulnerabilities and exploits!

Win7 isn't available from Microsoft anymore as a free VM, but I've included this lecture because you can still hack (and defend) a real Windows 7 computer, and there are millions of them still in use in businesses and homes - maybe even yours!

Intro to Metasploit
Setting up Guest Additions in VirtualBox
Creating an Exploit Payload with Metasploit
Sharing the Exploit over the Web
Running the Exploit to Hack Windows 7
Privilege Escalation: Gaining Root Access and Dumping Password Hashes
Metasploit & Meterpreter Review
Learn how to protect your password, and how to protect your information with simpler but BETTER passwords! Includes password cracking, hacking, snacking and hijacking!
Six Problems with Passwords
Hijacking Stored Passwords from Chrome and Firefox
Sniffing the Network: Installing Wireshark
Sniffing Unencrypted Passwords with Wireshark
Cracking Passwords with Kali and Online Tools
Seven Things You Can Do for Safer Passwords
Learn how to test for and how to prevent Cross-Site Scripting (XSS) and SQL Injection (SQLi) attacks using real-world examples.
Intro to Web Hacking
Hands-on Cross-Site Scripting (XSS) Attacks That Work!
SQL (Structured Query Language) Injection: Messing with Databases
Advanced SQLi Attacks

Good to know

Know what's good
, what to watch for
, and possible dealbreakers
Covers social engineering, which is standard in industry
Examines ethical hacking, which is highly relevant to cybersecurity
Explores car hacking, which is an emerging field
Teaches command-line tools and techniques, which are useful for both personal and professional growth
Develops mobile hacking skills, which are useful for those working in information security
Assumes some background knowledge of command-line tools and ethical hacking techniques

Save this course

Save Real-World Ethical Hacking: Hands-on Cybersecurity to your list so you can find it easily later:
Save

Activities

Be better prepared before your course. Deepen your understanding during and after it. Supplement your coursework and achieve mastery of the topics covered in Real-World Ethical Hacking: Hands-on Cybersecurity with these activities:
Configure a virtual ethical hacking lab
Setting up your own ethical hacking lab will give you hands-on experience with the tools and techniques used in the course.
Browse courses on VirtualBox
Show steps
  • Install VirtualBox on your computer
  • Download and install Kali Linux
  • Configure your virtual network settings
  • Create a new virtual machine and install Kali Linux
Learn basic Linux commands
Understanding basic Linux commands will help you navigate and use Kali Linux effectively.
Browse courses on Linux Commands
Show steps
  • Open a terminal window in Kali Linux
  • Learn how to navigate the file system using commands like cd and ls
  • Learn how to create and edit files using commands like touch, nano, and vim
  • Learn how to use basic commands like cat, grep, and awk to process text files
Practice social engineering techniques
Practicing social engineering techniques will help you understand how attackers can trick people into giving up their information.
Browse courses on Social Engineering
Show steps
  • Learn about different types of social engineering attacks, such as phishing and spear phishing
  • Create a fake website or email to simulate a phishing attack
  • Test your phishing attack on friends or family members (with their permission)
  • Analyze the results of your phishing attack and learn from your mistakes
Two other activities
Expand to see all activities and additional details
Show all five activities
Analyze malware samples
Analyzing malware samples will help you understand how malware works and how to protect yourself from it.
Browse courses on Malware Analysis
Show steps
  • Download a malware sample from a reputable source
  • Use a disassembler to analyze the malware sample and understand its code
  • Determine the purpose and functionality of the malware sample
  • Write a report on your analysis findings
Perform a vulnerability assessment on a website
Performing a vulnerability assessment on a website will help you identify and fix security vulnerabilities before attackers can exploit them.
Browse courses on Vulnerability Assessment
Show steps
  • Choose a website to assess
  • Use a vulnerability scanner to scan the website for vulnerabilities
  • Analyze the scanner results and identify the most critical vulnerabilities
  • Develop a plan to fix the vulnerabilities
  • Implement the plan and verify that the vulnerabilities have been fixed

Career center

Learners who complete Real-World Ethical Hacking: Hands-on Cybersecurity will develop knowledge and skills that may be useful to these careers:
Information Security Analyst
Information Security Analysts spend their days putting their knowledge of computer science, network security, and risk management to use to protect their employer's networks and data from unauthorized access and cyberattacks. To be successful in this role, it is important to have a deep understanding of the ethical guidelines and practices surrounding computer and network security, as well as the latest cybersecurity hacking techniques such as phishing and ransomware. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, introduces these important concepts, and will give you a solid foundation to build upon on your path to becoming an Information Security Analyst.
Penetration Tester
Penetration Testers are responsible for simulating cyberattacks on their employers' networks and systems in order to identify vulnerabilities and weaknesses. They then report their findings to management so that the vulnerabilities can be fixed. A deep understanding of ethical hacking techniques is critical to being successful in this role, and this course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, will give you the expertise you need to excel.
Security Consultant
Security Consultants help guide businesses in improving their cybersecurity through risk management and audits. In this role, you would work closely with clients to assess their cybersecurity needs and vulnerabilities, and provide recommendations on how to protect their data and networks. Knowledge of ethical hacking techniques such as phishing and social engineering can give you an edge on understanding how to test your clients' systems, and familiarity with security tools like Kali Linux is also a plus. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, will help you build the foundation you need to be successful in this role.
IT Auditor
IT Auditors assess organizations' information systems and controls in order to ensure compliance with laws, regulations, and internal policies. Ethical hacking is a valuable skill for IT Auditors, as it can help them identify vulnerabilities and weaknesses in an organization's systems and controls. The importance of cybersecurity and the prevalence of hacking in today's world make it more important than ever to have a solid understanding of ethical hacking techniques, and this course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, can help you gain that competitive edge.
Cybersecurity Engineer
Cybersecurity Engineers design, implement, and maintain cybersecurity systems and software. This role requires a deep understanding of cybersecurity principles and practices, as well as the ability to keep up with new technologies. This course _Real-World Ethical Hacking: Hands-on Cybersecurity_, is a great way to gain valuable cybersecurity knowledge and skills.
Network Security Engineer
Network Security Engineers design, implement, and maintain network security systems and software. This role requires a deep understanding of network security principles and practices, including ethical hacking techniques such as phishing and social engineering. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, is a great way to gain the knowledge and skills you need for this role.
Data Analyst
Data Analysts use data to solve business problems. They collect, clean, and analyze data to identify trends and patterns that can help businesses make better decisions. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful to those interested in Data Analyst roles, as it provides a foundation in data analysis and cybersecurity principles.
Computer Systems Analyst
Computer Systems Analysts analyze and design computer systems. This role requires a deep understanding of computer science principles and practices, as well as the ability to communicate effectively with both technical and non-technical stakeholders. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in Computer Systems Analyst roles, as it provides a foundation in computer science principles and cybersecurity practices.
IT Manager
IT Managers plan, implement, and manage IT systems and infrastructure. This role requires a deep understanding of IT principles and practices, as well as the ability to manage teams and projects. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in IT Manager roles, as it provides a foundation in IT principles and cybersecurity practices.
Information Systems Manager
Information Systems Managers plan, implement, and manage information systems and technology. This role requires a deep understanding of information systems principles and practices, as well as the ability to manage teams and projects. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in Information Systems Manager roles, as it provides a foundation in information systems principles and cybersecurity practices.
Network Administrator
Network Administrators manage and maintain computer networks. This role requires a deep understanding of networking principles and practices, as well as the ability to troubleshoot and resolve network issues. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in Network Administrator roles, as it provides a foundation in networking principles and cybersecurity practices.
Security Architect
Security Architects design and implement security systems and solutions. This role requires a deep understanding of security principles and practices, as well as the ability to work with a variety of stakeholders. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in Security Architect roles, as it provides a foundation in security principles and cybersecurity practices.
Software Engineer
Software Engineers design, develop, and maintain software systems. While this course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, is not directly related to software engineering, it may be useful for Software Engineers who are interested in learning about ethical hacking techniques and cybersecurity principles.
Systems Administrator
Systems Administrators manage and maintain computer systems and software. This role requires a deep understanding of computer science principles and practices, as well as the ability to troubleshoot and resolve system issues. This course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, may be useful for those interested in Systems Administrator roles, as it provides a foundation in computer science principles and cybersecurity practices.
Web Developer
Web Developers design and develop websites and web applications. While this course, _Real-World Ethical Hacking: Hands-on Cybersecurity_, is not directly related to web development, it may be useful for Web Developers who are interested in learning about ethical hacking techniques and cybersecurity principles.

Reading list

We've selected nine books that we think will supplement your learning. Use these to develop background knowledge, enrich your coursework, and gain a deeper understanding of the topics covered in Real-World Ethical Hacking: Hands-on Cybersecurity.
Fascinating look at the art of social engineering, the practice of manipulating people to gain access to information or resources. It must-read for anyone who wants to understand how hackers think and operate.
Classic guide to hacking, covering everything from the basics of computer security to advanced techniques for exploiting vulnerabilities. It valuable resource for anyone who wants to learn how to hack ethically.
Comprehensive guide to penetration testing, covering everything from reconnaissance to exploitation. It valuable resource for anyone who wants to learn how to hack ethically.
Comprehensive guide to web application security, covering everything from the basics of web application security to advanced techniques for exploiting vulnerabilities. It valuable resource for anyone who wants to learn how to hack web applications ethically.
Comprehensive guide to ethical hacking and penetration testing, covering everything from the basics of ethical hacking and penetration testing to advanced techniques for exploiting vulnerabilities. It valuable resource for anyone who wants to learn how to hack ethically.
Comprehensive guide to car hacking, covering everything from the basics of car security to advanced techniques for exploiting vulnerabilities. It valuable resource for anyone who wants to learn how to hack cars ethically.
Comprehensive guide to memory forensics, covering everything from the basics of memory forensics to advanced techniques for detecting malware and threats. It valuable resource for anyone who wants to learn how to investigate computer crimes.
Comprehensive guide to network security assessment, covering everything from the basics of network security assessment to advanced techniques for assessing network security. It valuable resource for anyone who wants to learn how to assess the security of their network.
Comprehensive guide to Metasploit, a popular penetration testing framework. It covers everything from the basics of Metasploit to advanced techniques for exploiting vulnerabilities.

Share

Help others find this course page by sharing it with your friends and followers:

Similar courses

Here are nine courses similar to Real-World Ethical Hacking: Hands-on Cybersecurity.
Kali Linux Concepts and Basic Functionality
Most relevant
Practice Your First Penetration Test: Kali & Metasploit...
Most relevant
Ethical Hacking using Kali Linux from A to Z
Most relevant
Kali Linux
Most relevant
Start Kali Linux, Ethical Hacking and Penetration Testing!
Most relevant
Ethical Hacking Fundamentals
Most relevant
The Complete Ethical Hacking Course 2.0: Python & Kali...
Most relevant
The Complete Ethical Hacking Course
Most relevant
LEARN ETHICAL HACKING AND PENETRATION TESTING 5 COURSES...
Most relevant
Our mission

OpenCourser helps millions of learners each year. People visit us to learn workspace skills, ace their exams, and nurture their curiosity.

Our extensive catalog contains over 50,000 courses and twice as many books. Browse by search, by topic, or even by career interests. We'll match you to the right resources quickly.

Find this site helpful? Tell a friend about us.

Affiliate disclosure

We're supported by our community of learners. When you purchase or subscribe to courses and programs or purchase books, we may earn a commission from our partners.

Your purchases help us maintain our catalog and keep our servers humming without ads.

Thank you for supporting OpenCourser.

© 2016 - 2024 OpenCourser