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Threats to security (2)

Threats to security (2). Level 2 Diploma Unit 11 IT Security. Categories of threats. Covered last week Weak external security Unauthorised uses Unauthorised removal or copying This week Malware Theft or loss Poor folder and file permissions. What is malware?.

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Threats to security (2)

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  1. Threats to security (2) Level 2 Diploma Unit 11 IT Security

  2. Categories of threats • Covered last week • Weak external security • Unauthorised uses • Unauthorised removal or copying • This week • Malware • Theft or loss • Poor folder and file permissions

  3. What is malware? • Malware - short for malicious software • a variety of forms of hostile, intrusive, or annoying software or program code • Virus • Worm • Trojan horse • Rootkit • Backdoor • Spyware • Botnet • Keystroke logger • Dialer • Adware

  4. Purpose of malware Started as experiments or pranks, such as the Melissa virus  Then changed to destroy files on a hard disk Worms vandalised web pages Originally spread on diskettes or in Word documents

  5. Melissa Virus Released 26th March 1999 Used stolen e-mail address Caused $80 million dollars damage E-mailed itself to 1st fifty addresses ‘Outlook’ with attachment such as list.doc Looked like e-mail from known associate Opened document infected normal.dot template

  6. Melissa virus • Sent document from your pc – data security breach, damage to trust, e-mail delays, cost of removal • When the day number equals the number of minutes in the current time (e.g., at 11:06 on the 6th day of the month), the Melissa virus inserted the following text in whatever document was then being edited in Word on the victim's computer: Twenty-two points, plus triple-word-score, plus fifty points for using all my letters. Game's over. I'm outta here.

  7. Purpose of malware • Given Internet access, malicious software is now designed for a profit • take control of users' computers for black-market exploitation • Infected "zombie computers" are used to • send email spam, • to host contraband data such as child pornography • engage in distributed denial-of-service attacks as a form of extortion

  8. Purpose of malware • Spyware programs • monitor a users' web browsing • display unsolicited advertisements • redirect money or advertising revenue to the spyware creator • Spyware programs do not spread like viruses • they are installed by • exploiting security holes • or are packaged with user-installed software, such as peer-to-peer applications

  9. Research Task • Give a definition and example of one of the following: • Virus • Worm • Trojan horse • Rootkit • Backdoor • Spyware • Botnet • Keystroke logger • Dialler • Adware • Phishing

  10. Virus or worm • Virus • a program that has infected some executable software and, when run, causes the virus to spread to other executables. • Viruses may contain a payload that performs other actions, often malicious. • A virus requires a user to trigger it spreading • Worm • a program that actively transmits itself over a network to infect other computers. • It may carry a payload • It does not require a user to do anything

  11. Trojan horses • Concealment helps get the malware installed • When a malicious program is disguised as something innocuous or desirable, users may be tempted to install it without knowing what it does. • Typical e-mail subject: "This is The Free Download Sex Movies, you can find it Here" • This is the technique of the Trojan horse or Trojan.

  12. Trojan examples • Torpig • affects Windows, turning off anti-virus applications. • allows access to the computer • modifies data • steals confidential information (such as user passwords and other sensitive data) • installs more malware on the victim's computer • has stolen the details of about 500,000 online bank accounts and credit and debit cards

  13. Rootkit • Once malware is installed, it needs to remain concealed • A rootkit: • Modifies the operating system kernel • Makes itself invisible in the task and process lists • May use the name of legitimate files • Makes its own files unreadable • Can run copies of itself and restart them if they are stopped

  14. Backdoors • A backdoor is • a method of bypassing normal authentication • malware can install one or more backdoors • allows easier access in the future for • Installation of more malware • Collecting saved key logger data • Triggering spam attacks

  15. Spyware • Spyware collects small pieces of information about users without their knowledge • Spyware programs can • collect Internet surfing habits • collect sites that have been visited • install additional software • redirect Web browsers • change computer settings, resulting in • slow connection speeds • different home pages

  16. Botnet • a collection of compromised computers (called zombie computers) • installed via worms, Trojans or backdoors • remotely controlled • botnets are rented out to • send out spam messages • perform denial of service attacks • billions of messages can be created per day 

  17. Key stroke loggers • Hardware • Connected between keyboard and PC • Can be wirelessly interrogated • Software • Malware based • Captures passwords, form submissions, clipboard, screen shots • Transmit data to web sites, e-mail or wireless

  18. Dialler • diallers connect non-broadband PCs • fraudulent diallers connect to premium-rate numbers • some diallers promise special content, such as: • software for download (usually illegal)  • trojans posing as MP3s • trojans posing as pornography, • programs such as cracks and keygens

  19. Adware • Software which automatically plays, displays, or downloads advertisements to a computer • Some adware can be classified as spyware e.g. BonziBUDDY • corrupted many of the user's system files • displayed obscene advertisements • logged browsing details and sent them to various third parties

  20. Loss or theft • Devices and data which are easily lost or stolen • Laptops • Mobile phones • USB drives and smart cards (flash memory) • CDs and DVDs

  21. Software errors • Failing to apply security patches • Automatic update turned off • Especially important for • Operating systems • Browsers

  22. Poorly written software • complexity increases the probability of operating system design flaws • default permissions grant every program and every user full access to the entire system • exploitable bugs in a software program • unchecked user input can allow unintended direct execution of commands or SQL statements

  23. Tasks (criteria P1, M1 and D1) • You have been put in charge of the security of the computing department’s IT systems • You have been asked to write a report • Describe the potential security threats that might damage the system and compromise its data (P1) • Evaluate which of these threats are the most likely to occur and give your reasons (M1) • Explain what the impact of these threats would be on the users of the system (D1)

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