Thursday 23 June 2011

Virus

Chapter 7 Virus

Computer virus are malicious programs that infect a computer system causing various problems with its use.

Viruses replicate and attach themselves to programs in the system.

There are more than 20,000 different computer viruses with the number growing daily.

How virus infections spread by:
  • Inserting a disk with an infected program and then starting the program.
  • Downloading an infected program from the Internet.
  • Being on a network with an infected computer.
  • Opening an infected e-mail attachment.
Type of Viruses:

File Infectors; the most common type of virus, usually attach themselves to program files and spread to other programs on the hard drive.

Boot Sector Viruses usually attach themselves to the boot sector of a hard drive. They are executed each time the computer is started and this may lead to destruction to all data.

Macro Viruses infect automatic command capabilities of productivity software. They usually attach themselves to the data files in word processing, spreadsheet, and databases programs thus will be spread when the data files ares exchanged between users.

More rogue programs:

Time bombs (also known as logic bombs). They are harmless until a certain event or circumstance activates the programs.

Worms resemble viruses. They are spread from one computer to another. They control infected computers. and attack other networked computers.

Denial of Service Attack (DoS) is when the syn is flooding. It overload an Internet server with a large number of requests.

Trojan Horses disguise themselves as useful programs but actually they contain hidden instructions. They may erase data or cause other damage.

Fraud and Theft

Like selling social security numbers and etc.

Memory shaving is taking RAM chips from computers.

Salami shaving is when a programmer alters a program to take a small amount of money out of an account.

Data Diddling is when data is altered to hide theft.

Techniques to Obtain Passwords:
  • Password guessing.
  • Shoulder surfing.
  • Packet sniffing.
  • Dumpster diving.
  • Social engineering.
  • Superuser status.

I think that's all covered for this topic... since it's a half an hour replacement class...

Tomorrow is the final session.. and the carry marks will be released..

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