ITMA05 Computer Security


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ITMA05 Computer Security

  1. 1. 11/17/2008 Big IT Firm Gets It! ITMA Fall 2008 K.Ng From 17-Nov-08 ITAM K.Ng 1 17-Nov-08 ITAM K.Ng 2 In the News… In the News… 明報14Oct2008 都市日報 4 Nov 2008 17-Nov-08 ITAM K.Ng 3 17-Nov-08 ITAM K.Ng 4 And remember this? Even President gets it… 17-Nov-08 ITAM K.Ng 5 17-Nov-08 ITAM K.Ng 6 1
  2. 2. 11/17/2008 What you will learn? What is computer security?  Types of threats  Protection of computing systems and  Guidelines on protecting yourself the data that they store or access. 17-Nov-08 ITAM K.Ng 7 17-Nov-08 ITAM K.Ng 8 What could happen if your computer is Why is it important? compromised?  Enable you to carry out your duties 1. Could be used to hide programs that launch attacks on other computers.  Protect personal and sensitive info. 2. Could be generating large volumes of unwanted traffic, slowing down the entire system. 3. Someone could be distributing illegal software from your computer. 4. Someone could access personal info. From your computer. 5. Someone could record all of your keystrokes and get your passwords. 17-Nov-08 ITAM K.Ng 9 17-Nov-08 ITAM K.Ng 10 Answer? It is NOT just an IT problem  All of the above!  10% of security safeguards are technical.  90% of security safeguards rely on the computer user to observe good practices. IT Security is everyone’s responsibility!!! 17-Nov-08 ITAM K.Ng 11 17-Nov-08 ITAM K.Ng 12 2
  3. 3. 11/17/2008 Social Engineering Three common examples  The practice of obtaining confidential info. by 1. Spam scams: deceptive emails to get people manipulation of legitimate users. to reveal info.  Users are the weakest link in security.  “They” will use the telephone, Internet, email to 2. Impersonation: pose as someone in authority trick people into revealing sensitive info. or get or IT personnel to obtain info. or access to them to do something against the policy. systems.  For more info:  3. Dumpster diving: go thro’ trash to obtain  “The Art of Deception”, Kelvin Mitnick, 2003. valuable info.  Movie (2000) & book (1996) “Takedown” 17-Nov-08 ITAM K.Ng 13 17-Nov-08 ITAM K.Ng 14 Case (1) Safely destroy files on HD?  Mr Chapman found important  This? personal data on a computer • he bought on ebay.  Affected a million bank  Or this? customers from RBS, • NatWest, AmEx.  Or this?  Under investigation by the Info • Commissioner £35 from eBay! From Daily Mail UK, 27Aug08 17-Nov-08 ITAM K.Ng 15 17-Nov-08 ITAM K.Ng 16 Cheaper solutions… Spam scams   Phishing  Email asks you to go to a website to update your  personal info.  Phishing scam archive ○  Phony security alert  Emails or pop-up windows warn that your computer is at risk of being infected or hacked and contain an attachment or link to a patch to fix the problem.  Nigerian bank account scam  Collect your money and bank account info. 17-Nov-08 ITAM K.Ng 17 17-Nov-08 ITAM K.Ng 18 3
  4. 4. 11/17/2008 Examples of phone prank Sarah Palin called by Nicolas!  A very popular radio program in the late 80s.  軟硬天師 整蠱電話  e.g. 17-Nov-08 ITAM K.Ng 19 17-Nov-08 ITAM K.Ng 20 Avoid social engineering Computer Viruses  DO NOT give sensitive personal info. to anyone you don’t know or who doesn’t have a legitimate need for it.  Destroy or securely erase sensitive info. before recycling or throwing it away.  Delete unsolicited emails immediately.  Sounds too good to be true? It is!  Report to the authority. 17-Nov-08 ITAM K.Ng 21 17-Nov-08 ITAM K.Ng 22 What is it? Types of viruses (i)  A self-replicating program that spreads  Macro Viruses by inserting copies of itself onto other  Use command (macros) embedded in other executable code or documents. software to infect and spread to other files viewed by that software, e.g. Word/Excel.  It will perform a function, e.g. delete certain files. 17-Nov-08 ITAM K.Ng 23 17-Nov-08 ITAM K.Ng 24 4
  5. 5. 11/17/2008 Macro Protection in Word 2007 Types of viruses (ii)  Worms  Duplicate themselves and use communications such as emails to spread. They can look at your email address book and send themselves to users in your address book. 17-Nov-08 ITAM K.Ng 25 17-Nov-08 ITAM K.Ng 26 Worms examples Type of viruses (iii)  Spyworm.Win32  File viruses  Attach themselves to other software. When the software is run, the virus first loads itself into memory so that it can further infect other files or begin damaging the computer.  Trojan  Programs that claim to perform a particular function but in fact do something different 17-Nov-08 ITAM K.Ng 27 17-Nov-08 ITAM K.Ng 28 Type of viruses (iv) Example  Backdoor Trojans  “I Love You” and “Bagle” worms  Programs that allow other computer users to  They spread themselves via email remotely control your computer via attachments. networks.  It sends an email with itself as an  Boot Sector Viruses attachment to everyone in that computer’s  Infect a computer’s startup program so that email address books. the virus would become active as soon as  Worms are also often designed to use up the computer started up. resources on that computer, such as, memory and processing power. 17-Nov-08 ITAM K.Ng 29 17-Nov-08 ITAM K.Ng 30 5
  6. 6. 11/17/2008 Virus Scanners Malware  Online scanner  A general term for software that is  installed on your computer without your knowledge and often your consent to perform various tasks.  Free (non-commercial use)  Grisoft’s AVG  Avira AntiVir Personal  Avast! Home Ed. 17-Nov-08 ITAM K.Ng 31 17-Nov-08 ITAM K.Ng 32 Types of Malware Malware scanners  Adware  Lavasoft Ad-Aware 2008 Free  Annoying pop-ups, install IT menu bars,  targeted ads. according to your online  Spybot Search and Destroy shopping habits or surfing habits.   Spyware  Microsoft Windows Defender (with Vista)  Collects user details, such as, passwords,  credit card info. fender/default.mspx  Pop-up windows with active-x control. 17-Nov-08 ITAM K.Ng 33 17-Nov-08 ITAM K.Ng 34 Good Password Good password  At least 8 characters containing 3 of the  Or a passphrase at least 10 characters following 4 categories:  A memorable phrase, e.g. song or book title,  Lower case letters (a-z) line of poetry…etc.  Upper case letters (A-Z)  A phrase that has personal meaning but  Numbers (0-9) might not appear widely.  Special characters (! # ? /)  e.g. a random line from your favorite movie.  Combining phrases is better. 17-Nov-08 ITAM K.Ng 35 17-Nov-08 ITAM K.Ng 36 6
  7. 7. 11/17/2008 Bad password  A word found in dictionary, whether spelled forwards or backwards, or a word preceded or followed by a digit (e.g. secret1, 1terces) Demo:  Include user name or login name  Include personal info: family names, A phrase into a password places, pets, birthdays, address, hobbies, phone nos. …etc.  Slang, dialect, jargon…etc.  Keyboard sequences, e.g. qwerty, asdfg, abc123…etc. 17-Nov-08 ITAM K.Ng 37 17-Nov-08 ITAM K.Ng 38 Password security guidelines More on password  Never share your password with anyone  How to create passwords else for any reason.   Passwords should not be written down, ssword/create.mspx stored electronically (e.g. browser) or published.  Test your password strength  Use different passwords for different  accounts. ssword/checker.mspx  Change password regularly. 17-Nov-08 ITAM K.Ng 39 17-Nov-08 ITAM K.Ng 40 Firewall What is it?  It inspects network traffic passing through it, and denies or permits passage based on a set of rules. 17-Nov-08 ITAM K.Ng 41 17-Nov-08 ITAM K.Ng 42 7
  8. 8. 11/17/2008 Types of firewall  Packet filter  Stateful packet inspection (SPI)  Pass/drop individual packets according to a  Examine packets in groups rather than set of rules individually.  Inspect source and destination IP and port  Avoid attacks like SYN Floods, DoS Port Description  Application layer 21 FTP File Transfer Protocol  Filter traffics on the application level 23 Telnet 25 SMTP Simple Mail Transfer Protocol 80 HTTP 110 Post Office Protocol (POP3) 443 HTTPS 17-Nov-08 ITAM K.Ng 43 17-Nov-08 ITAM K.Ng 44 Network address translation Managing firewalls = A Profession (NAT)  Translate address to private range  Enterprise-class firewalls  –  CheckPoint  –  Juniper (Netscreen)  – ○ index.html  Security Certifications  e.g. CISSP from (ISC)2 , CISA 17-Nov-08 ITAM K.Ng 45 17-Nov-08 ITAM K.Ng 46 Sending info. Over the internet Wireless security (Access Point) securely  Change your AP’s admin. login/Pwd  Watch this  Change your default SSID  secure-site-using-ssl.aspx  Disable SSID Broadcast  Encryption: WPA-PSK, avoid old WEP  Demo – online shopping  Media Access Control (MAC) Authentication   Disable DHCP 17-Nov-08 ITAM K.Ng 47 17-Nov-08 ITAM K.Ng 48 8
  9. 9. 11/17/2008 Encryption (1) Encryption (2)  Private Key Encryption  Public Key Encryption  Encrypt a message  Bob sends a secret message to Alice  Encrypt a file  Problems with private key? Diagrams from wikipedia 17-Nov-08 ITAM K.Ng 49 17-Nov-08 ITAM K.Ng 50 12 Good IT Practices Cont’ (1) 1. Choose good passwords and protect 6. Shut down, lock, log off before leaving it them unattended, and make sure it requires a 2. Cautious when using internet password to start-up. 3. Safe emailing 7. Make sure your computer is protected 4. Secure your area before leaving it with anti-virus, security patches, unattended updates…etc. 5. Secure your portable computer at all 8. Don’t keep sensitive info. on portable times devices. 17-Nov-08 ITAM K.Ng 51 17-Nov-08 ITAM K.Ng 52 Cont’ (2) Conclusion 9. Don’t install or download unknown or  This is only a very short introduction unsolicited programs to your computer  Remember to protect yourself at all times. 10. Avoid using P2P programs, e.g.  … and Internet is like , not safe. FOXY…etc. 11. Don’t use illegal software.  References: 12. Make backup copies of files or date you  are not willing to lose --- and store the  copies very securely. modified from 17-Nov-08 ITAM K.Ng 53 17-Nov-08 ITAM K.Ng 54 9