Computer Security

Computer Security

1. TYPES

   • Active
     • Actions to protect
   • Passive
     • Minimises impact of damage

2. To use computers:

   • Know how to
     • Apply security tools
   • Know security tools

3. Malicious Software

   • Malware: Software with malicious purposes.
     • Types
       • Virus
         • Harmful self-installing program. Can self-replicate and infect other systems. Spreads: Portable drives, software, Internet. Best known and most important.
       • Keylogger
         • Attempts to obtain and memorize keystrokes. Remote spying to obtain passwords.
       • Worm
         • Floods system´s memory by reproducing itself.
       • Spyware
         • Not all are malicious.
         • Trojan
           • Conatins instructions, camouflages. Destroys or gathers information saved on disks.
         • Adware
           • Advertising in programs after installation. Can be spyware and pass user´s info to other parties.
         • Hijackers
           • Programs that "Hijack" other programs to use their rights or change their behaviour.
   • Signs of attack
     • Slow processes/Internet connection
       • Less disk space
         • Unknown programs/icons
           • Keyboard/mouse act strange

4. More Terminology

   • Hackers
     • Theoretically, intellectual challenge-seeking criminals. - Ethical Hacking: show how secure you are against malicious hackers. - Black Hackers: attack internet security systems to make profit.
   • Crackers
     • People who pirate (use without license) programs by changing how it works to obtain valid serial numbers.
   • Cookies
     • Saved text files by browser when  visiting a website for the site to read them on subsequent visits. Not a threat as long as only aim is to provide access to the site. Non-malicious spyware.
   • Pharming
     • Redirecting a domain name to a different computer so a user who enters the URL goes to the attacking website.  Can replace a bank website to obtain passwords.
   • Hoaxes
     • Company started chain e-mails to gather addresses and carry out e-mails. Not illegal. Ex: Company sends one such as "Lost Child!", or "Careful, dangerous virus!" to millions of invented addresses. Some resend the message and it reaches the company again, now full of valid e-mails.
   • Spam
     • E-mails that flood networks to advertise products (sometimes illegal ones) so recipients buy them. Represents 80% of e-mail traffic world-wide because 1 in 12 million reply positively.

5. Protection

   • Antivirus
     • Program that analyses different units and devices and incoming and outgoing data flows, checking file codes and looking for character fragments. Detects viruses and only sometimes identifies them. Protect from viruses, trojans and worms, most have antispyware and sometimes spam filters.
   • Firewall
     • Controls and filters network traffic through ports. Provide alerts asking for confirmation for any program that uses internet; important to set up logically.
   • Proxy
     • Entry port-functioning software. Can be fireball or website blocker.
   • Passwords
     • Help protect security of file, folder or computer. Recommended between 6-8 characters.
   • Cryptography
     • Encrypting of info. to protect files, communications and passwords.
   • Preventing Attacks
     • Make backups of system
       • Secure passwords
         • Open trusted Wi-fi networks.
           • Antivirus
             • Update operating system
               • Check plugged devices
                 • Carefully download files
                   • Firewall