1. ITS220 – How To Prevent Your PC From Infected by Virus presented by Desmond Ho

2. Objectives Introduce ways of virus attacks. Suggest the good practice of using your computer and the Internet. Introduce prevention methods for protecting your PC from virus attacks. Advice when the computer is getting infected.

3. What is virus? A program written intentionally to enter a computer without the user's permission or knowledge. Virus continues to spread, replicate itself and causes serious damage or affects program and system performance.

4. Different ways of virus attacks 1.Trojan horse 2.Email attachment 3.Macros E.g. MS Word, MS Excel 4.Visiting websites 5.Network attacks E.g. DDOS

5. How to prevent virus? 1.Install anti-virus software. 2.Update virus signature regularly. 3.DO NOT VISIT suspicious web sites. 4.DO NOT DOWNLOAD un-trusted software from Internet. 5.DO NOT EXECUTE files from doubtful origins. 6.DO NOT OPEN an e-mail attachment unless you know who sent it. 7.DO NOT OPEN or FORWARD suspicious emails, delete them immediately. 8.Regularly back-up your files.

6. Helping hands 1.Anti-Virus 2.External firewall −Hardware router −Anti-virus appliance, Intrusion detection system, Intrusion prevention system 3.Personal firewall 4.Anti-Spyware 5.Anti-Spam

7. 1. Anti-Virus Commercial anti-virus software −Mcafee, Norton, Trendmicro Free anti-virus software −http://free.grisoft.com/freeweb.php/doc/2/ −http://www.free-av.com/ Online anti-virus scanner −http://housecall.trendmicro.com/ −http://us.mcafee.com/root/mfs/default.asp?cid=9914 Remember to turn on the automatic update feature.

8. 2. External firewall Hardware based firewall can fine control the Internet traffic flowing to and fro your computer. Require expertise to setup. Usually employed in corporate environment.

9. 3. Personal firewall Use personal firewall to hide your computer from Internet outlaws. −Windows XP internal firewall −Free ZoneAlarm http://www.zonelabs.com −Norton Personal firewall

10. 4.1 Anti-Spyware International Data Corp. reported 67% of all computers are infected with some form of spyware in 2004. Spyware is the 4th-greatest threat to a network security.

11. 4.2 Anti-Spyware Spyware, also known as adWare, malware secretly gathers information and relays it back to advertisers or hackers. They can track your surfing habits, hijack your browser start page, alter important system files. Spyware infects a computer through a virus or through the installation of new software.

12. 4.3 Anti-Spyware Functions of anti-spyware −Block pop-up ads −Remove back doors −Guard against unknown program entrance

13. 4.4 Anti-Spyware Free anti-spyware −http://www.lavasoftusa.com/support/download/ −http://www.microsoft.com/athome/security/spyware/software/default.mspx

14. 5.1 Anti-Spam Spam, the unwanted junk email that clogs up your email account, affects nearly everyone daily. Self defined keywords filtering DNS Blacklist

15. 5.2 Anti-Spam Consider using an Internet service provider or an email service that includes anti-virus and spam filtering as your first line of defense. E.g. hotmail, yahoo mail

16. 5.3 Anti-Spam Support POP3 Free: −http://www.spampal.org/ Commercial: −http://www.symantec.com/

17. Ways to detect virus infection Watch out for changes in machine behaviour. Scan the hard disk with an anti-virus software. Employ server-based anti-virus software to protect the network.

18. What to do if infected? Stop using the infected machine (and it should be detached from the network). Continuing the use of the infected machine help the suspected virus spread further. Recover from backup is the most secure and effective way to recover the files. In case you do not have the latest backup of files, you may try to remove the virus using anti-virus software.

19. Reference web sites http://www.hkcert.org/ http://windowsupdate.microsoft.com