A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user.
The original may modify the copies or the copies may modify themselves, as occurs in a metamorphic virus.
A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or carrying it on a removable medium such as a floppy disk, CD, or USB drive.
A virus can only spread from one computer to another when its host is taken to the uninfected computer, for instance by a user sending it over a network or carrying it on a removable medium such as a floppy disk, CD, or USB drive.
Additionally, viruses can spread to other computers by infecting files on a network file system or a file system that is accessed by another computer.
Viruses are sometimes confused with computer worms and Trojan horses.
A worm, however, can spread itself to other computers without needing to be transferred as part of a host.
A worm, however, can spread itself to other computers without needing to be transferred as part of a host.
A Trojan horse is a file that appears harmless until executed. In contrast to viruses, Trojan horses do not insert their code into other computer files.
Many personal computers are now connected to the Internet and to local-area networks, facilitating their spread.
Many personal computers are now connected to the Internet and to local-area networks, facilitating their spread.
Today's viruses may also take advantage of network services such as the World Wide Web, e-mail, and file sharing systems to spread, blurring the line between viruses and worms. Furthermore, some sources use an alternative terminology in which a virus is any form of self-replicating malware.
SPYWARE:
Spyware is computer software that collects personal information about users without their informed consent.
The term Spyware, which was coined in 1995 but wasn't widely used for another five years, is often used interchangeably with adware and malware (software designed to infiltrate and damage a computer respectively).
Personal information is secretly recorded with a variety of techniques, including logging keystrokes, recording Internet web browsing history, and scanning documents on the computer's hard disk.
Personal information is secretly recorded with a variety of techniques, including logging keystrokes, recording Internet web browsing history, and scanning documents on the computer's hard disk.
Purposes range from overtly criminal (theft of passwords and financial details) to the merely annoying (recording Internet search history for targeted advertising, while consuming computer resources).
Spyware may collect different types of information. Some variants attempt to track the websites a user visits and then send this information to an advertising agency.
Spyware may collect different types of information. Some variants attempt to track the websites a user visits and then send this information to an advertising agency.
More malicious variants attempt to intercept passwords or credit card numbers as a user enters them into a web form or other applications.
SPAM:
Spamming is the abuse of electronic messaging systems to send unsolicited bulk messages, which are generally undesired.
While the most widely recognized form of spam is email spam, the term is applied to similar abuses in other media: instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, mobile phone messaging spam, internet forum spam and junk fax transmissions
PISHING:
Phishing is essentially an online con game and phishers are nothing more than tech-savvy con artists and identify thieves.
They use SPAM, malicious Web sites, email messages and instant messages to trick people into divulging sensitive information, such as bank and credit card accounts.
TROJAN:
In the context of computer software, a Trojan horse is a program that unlike a virus contains or installs a malicious program (sometimes called the payload or trojan).
The term is derived from the classical myth of the Trojan Horse.
There are two common types of Trojan horses.
One is otherwise useful software that has been corrupted by a hacker inserting malicious code that executes while the program is used.
Examples include various implementations of weather alerting programs, computer clock setting software, and peer to peer file sharing utilities.
The other type is a standalone program that masquerades as something else, like a game or image file, in order to trick the user into some misdirected complicity that is needed to carry out the program's objectives.
