ITIS 1210 Introduction to Web-Based Information Systems

1. ITIS 1210Introduction to Web-Based Information Systems Chapter 45 How Hackers can Cripple the Internet and Attack Your PC

2. Introduction • Hackers attack targets of opportunity • Individuals • Corporate Web sites • ISPs • Why? • Might want to shut down a site • Revenge • Prove they can

3. Denial of Service • DOS attacks attempt to shut down a site • DDOS – Distributed Denial of Service • Incapacitates a network by flooding it with extraneous traffic • Might be requests for service

4. Denial of Service • Smurf attack • Uses ICMP – Internet Control Message Protocol • Fraggle attack • Re-write of a Smurf attack using UDP – User Datagram Protocol

5. How Hackers Can Attack Your Computer • Example uses SubSeven • Installed via a virus onto your computer • Opens port 7374 • Hacker can query your computer to see if port 27374 is open • If so, they have access as if they were sitting at your keyboard

6. How Hackers Can Attack Your Computer • Hacker can • Copy or delete files or programs • Examine and use personal data, credit card information, for example • Access your passwords • Upload files to your computer • Store illegal files on your computer and direct others to access them from you • Use your computer to launch attacks

7. How Email Viruses Travel in Your Email • Malware authors are often good social engineers • They know what kinds of things we will respond to • Cute • Greed • “Personal” • Hidden with the email could be any of a number of types of viruses

8. How Email Viruses Travel in Your Email • Attachment virus • Pretends to be something like a photo, sound, or movie file • May be able to determine based on file name of attachment • Example: Melissa virus • HTML virus might be active content • Used in processing forms, other interactivity

9. How Email Viruses Travel in Your Email • MIME virus • Mul.ti-Purpose Internet Mail Extension • Takes advantage of security vulnerabilities in Outlook Express and Internet Explorer • Forms in the email header contain more content than will fit in buffer • Overflow content spills into another holding area from which the processor talkes its instructions • Virus is then executed as if it were legitimate code

10. How Email Viruses Travel in Your Email • Viruses attack in different ways • Attachment virus launches when attachment is run, usually by double-clicking the attachment • HTML viruses run when the user opens the message to read it • Might run when viewed in the preview window • MIME viruses can run without the user doing anything

11. How Email Viruses Travel in Your Email • Typical virus first propagates itself • Searches address book, old email, even documents • Identifies names and addresses • Sends duplicates of itself to those addresses • This process repeats itself on all those destination computers

12. How Email Viruses Travel in Your Email • Results might be just an irritating message or something much more serious • Deleted files • Slow processing

13. How Zombies and Bot Networks Work • A zombie or a bot is a computer that can be controlled by someone remotely • A single controller might have a network of thousands of infected computers • A typical zombie connects to an IRC (Internet Relay Chat) channel • Lets controller know it is available

14. How Zombies and Bot Networks Work • Controller sends commands telling all his/her zombies to perform a certain command • Send out a spam or phishing attack • Because attacks are carried out by the zombies, the actual attacker is insulated • Attacks can’t be traced back to him/her

15. How Zombies and Bot Networks Work • After the attacks, the zombies can be placed into hibernation until needed again • Attackers look for computers with constant network cnnections (DSL or RoadRunner) and fairly high-speed connections

16. How Hackers Exploit Browsers • Browser attacks take advantage of security vulnerabilities in certain commonly-used browsers • Internet Explorer • Firefox • Buffer overflow attack • Buffers are areas of memory used to hold data

17. How Hackers Exploit Browsers • Buffer overflow attack (cont.) • If too much data is placed into the buffer it overflows into adjacent areas of memory • That data might be malicious code that can executed as if it were a normal program • Malicious code can damage computers in numerous ways • Allows a hacker to gain control

18. How Hackers Exploit Browsers • Drive-by downloads often occur without the user’s knowledge • Might be spyware or a Trojan • Often infects a computer as a result of clicking a pop-up generated by a Web site you’re visiting.

19. How Hackers Exploit Browsers • ActiveX is often used • A way to allow software to be downloaded and run inside the browser • Can be used to steal information, install spyware, run Trojans, etc.