1. Chapter 4 Hackers: How they get into Computers

2. Synopsis (I) What is a hacker? What is a cracker and what is the difference? Who are the crackers? What damage can crackers do? Typical cracker targets Cracker Motivations Cracker tools

3. Synopsis (II) Firewalls Software Firewalls Hardware Firewalls How to detect a cracker attack How to fix a cracker attack Ten minute fixes

4. What is a hacker, what is a cracker and what is the difference? Hacker has different meanings depending on who uses it. It had different traditional meanings, see http://www.thefreedictionary.com/hack http://www.thefreedictionary.com/hack Among programmers, it is a sign of pride. However, some (specially MIT hackers) have “crossed over”, giving the term a negative connotation. Still, some people prefer to use the term “cracker” for the bad kind, “hacker” for the ingenious kind, but the distinction is murky, at best.

5. Who are the crackers? Hackers are geeks. Hackers and crackers are highly intelligent social misfits who have a strong curiosity, and an anarchistic/anti-authoritarian bent. The belief among hackers that information should be free is widespread. Two kinds of crackers: people developing tools and script-kiddies.

6. What damage can crackers do? Vandalism Hacktivism Theft of of intellectual or proprietary technology or information. Hijacking Computers Identity theft Cyber-terrorism

7. Typical cracker targets Corporate networks Web servers/web sites Personal computers: can be used fo:  DOS attacks  Spam emailing  Storage

8. Cracker Motivations The thrill of it. Economic Some have a political or social agenda

9. Cracker tools Trojan horse Virus Worm Vulnerability scanner Sniffer Social Engineering Rootkits Software exploits

10. Synopsis (II) (defenses) Firewalls Software Firewalls Hardware Firewalls How to detect a cracker attack How to fix a cracker attack Ten minute fixes

11. Firewalls Like an electronic wall customs inspector that only allows some information through.  Usually determined by “port number” (loosely related to addressed program, but sometimes more information is used). Two kinds of firewalls:  Software  Hardware

12. Software Firewalls Ideally  Easy to configure  Frugal with system resources  Doesn't bug you too much Windows Firewall Third Party Firewalls Mac and Linux Firewall

13. The Windows Firewall Invisible Silent Will only tell you if an unrecognized program tries to access the internet (on Vista, W7) Doesn't slow down the system But:  Outbound traffic not examined  Only minimally configurable (unless you are an alpha geek)

14. Third Party Firewalls Two way filtering Intuitive advice Custom alert levels Stealth mode Threat management (inspect for malware) Recommendations  PC Tools Firewall Plus  Zonealarm: http://www.zonealarm.comhttp://www.zonealarm.com  Comodo: http://personalfirewall.comodo.com/free- download.htmhttp://personalfirewall.comodo.com/free- download.htm

15. Hardware Firewalls Advantages:  Fire and forget  Included in the price and functionality of your router  Have no impact on your computer Use NAT.  Stateful inspection

16. How to detect a cracker attack Appearance of strange data Your computer may start sending large volumes of data or spam You may be ID thieved.

17. How to fix a cracker attack The only real fix is a re-install

18. Ten minute fixes Deep search and destroy. Turn on logs Turn on firewalls.