System Attack Methods
Attackers develop new attack methods as fast as new products and technologies are introduced. It seems as though as soon as something new and cool comes out, only days — or even hours — later, you hear that someone has found a way to attack it.
As soon as data found a way to move easily from computer to computer, a creative individual with a bad attitude figured out that he could include some code that would play a not-so-practical joke, such as delete or alter files on someone else’s computer. And more recently, criminal organizations have figured out that they can steal valuable information — such as bank account numbers and credit card numbers, or the login credentials to high-value sites such as online banking — from peoples’ computers.
Unfortunately, several types of malicious code are out there; we define the most interesting ones here.
The main purpose of a computer virus, a (usually) small program, is to replicate itself. Early computer viruses attached themselves to floppy disks’ boot sectors or to executables (such as
.exe files). Boot-sector viruses spread if a user booted the PC with an infected diskette. Viruses attached to executable files would spread when a user ran those executable files. Multi-partite viruses spread by using both the boot sector and executable files.