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

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

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

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

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

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

How Viruses Travel in Your  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

How Viruses Travel in Your  MIME virus  Mul.ti-Purpose Internet Mail Extension  Takes advantage of security vulnerabilities in Outlook Express and Internet Explorer  Forms in the 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

How Viruses Travel in Your  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

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

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

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

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

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

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

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

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.

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.