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Threats Explained
Definitions of Malware

Virus - Worm - Adware - Spyware - Phishing - Rootkit - Scam - Hoax

Virus
Viruses have used many sorts of hosts. When computer viruses first originated, common targets were executable files that are part of application programs and the boot sectors of floppy disks. More recently, most viruses have embedded themselves in e-mail as Email attachments, depending on a curious user opening the viral attachment. In the case of executable files, the infection routine of the virus arranges that when the host code is executed, the viral code gets executed as well. Normally, the host program keeps functioning after it is infected by the virus. Some viruses overwrite other programs with copies of themselves which destroys them altogether. Viruses can spread across computers when the software or document they've attached themselves to is transferred from one computer to the other.

Worm
Computer worms are similar to viruses but are stand-alone software and thus do not require host files (or other types of host code) to spread themselves. They do modify their host operating system, however, at least to the extent that they are started as part of the boot process. To spread, worms either exploit some vulnerability of the target system or use some kind of social engineering to trick users into executing them.

Adware
Adware or advertising-supported software is any computer program or software package in which advertisements or other marketing material are included with or automatically loaded by the software and displayed or played back after installation or in which information about the computer or its users activities is uploaded automatically when the user has not requested it. These applications often present banner ads in pop-up windows or through a bar that appears on a computer screen.

Spyware
Spyware is an emerging class of malicious software that intercepts or takes partial control of a user's computer without his informed consent. The purpose of spyware is to transfer knowledge about the computer and its user to an external party. Spyware can have many side effects, including identity theft.

Phishing
In computing, phishing (also known as carding and spoofing) is a form of social engineering, characterised by attempts to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business in an apparently official electronic communication, such as an email or an instant message. The term phishing arises from the use of increasingly sophisticated lures to "fish" for users' financial information and passwords.

Rootkit
A rootkit is a collection of one or more tools designed to covertly maintain control of a computer. The rootkit may include tools to obtain access to the computer as well. When installed a rootkit uses functions in the operating system to hide itself, so as not to be detected.
The rootkit will usually hide other files, such as keystroke loggers and/or other malicious programs.
Rootkits first were used in Unix, but now are also used in Linux, Windows, and other operating systems. Rootkits may be used for legitimate purposes such as Law Enforcement, but are generally known for their unauthorized use.

Scams
How to Spot a Scam
• If you didn’t opt-in— legitimate charities only send appeals to individuals who have explicitly chosen to receive emails from the organization. Unsolicited, such emails are almost always fraudulent.
• Don’t be fooled by appearance—emails can appear legitimate by copying the graphics and language of a legitimate organization. Many include tragic stories of victims of the disaster.
• Don’t click through to links—links in emails can lead to “spoofed” Web sites that mirror the look and feel of a genuine organization.
Hoaxes

 
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