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Tools and Resources

Computer Security Glossary

Below is a list of terms and phrases commonly associated with types of computer viruses, spyware and adware. Learn the facts and protect yourself from Internet dangers and security threats.


is advertising-supported software that displays pop-up advertisements. Adware is usually available via free downloads from the Internet. Adware is often bundled with or embedded within freeware, utilitarian programs like filesharing applications, search utilities, information-providing programs (such as clocks, messengers, alerts, weather, and so on), and software such as screensavers, cartoon cursors, backgrounds, sounds, etc. Although seemingly harmless, some adware programs may track your Web surfing habits. Deleting adware may result in the deletion of the bundled freeware application.


Software products designed to detect, remove or disable existing spyware infections and/or and prevent spyware installation.

Anti-spyware software

Protects a PC from spyware infection. Spyware protection software will find and remove spyware without system interruption.

Anti-virus download

An anti-virus software program available for download.


A user-generated, shared online journal where people can post diary entries about their personal experiences and hobbies; "postings on a blog are usually in chronological order. Derived from "Web log," "blog" can also be used as a verb, meaning to maintain or add content to a blog.


An application program that allows the user to examine encoded documents in a form suitable for display, esp. such a program for use on the Web.

Browser hijacker

A spyware program that resets a user's homepage so each time the browser is launched, the user lands on the site determined by the spyware.


An error, flaw, mistake, failure, or fault in a computer program that prevents it from behaving as intended (e.g., producing an incorrect result). Most bugs arise from mistakes and errors made by people in either a program's source code or its design, and a few are caused by compilers producing incorrect code.


Pieces of information generated by a Web server and stored on your computer for future access. Cookies were originally implemented to allow you to customize your Web experience. However, some sites now issue adware cookies, which allow multiple sites to store and access cookies that may contain personal information (surfing habits, usernames and passwords, areas of interest, etc.), and then simultaneously share the information with other sites. Adware cookies are installed and accessed without your knowledge or consent.

Credit card fraud

When credit card fraud occurs, a merchant (business, service provider, seller, etc.) is tricked into releasing merchandise or rendering services, believing that a credit card account will provide payment. The merchant later learns that they will not be paid, or that the payment they received will be reclaimed by the card's issuing bank. A fraudulent or stolen credit card is charged for the purchase. Today, half of all credit card fraud is conducted online using spyware.


The primary display screen of a graphical user interface, on which various icons represent files, groups of files, programs, or the like, which can be moved, accessed, added to, put away, or thrown away in ways analogous to the handling of file folders, documents, notes, etc., on a real desk.


An application that typically installs itself without user consent.  Once installed, dialers are designed to run up phone bills by automatically dialing long distance and 900 numbers.  While the do not spy on you, they will rack up significant long distance phone charges.


To transfer software, data, character sets, etc. from a remote system, such as a Web site, FTP server, or other similar system, or to transfer from a nearby computer, from a larger to a smaller computer, or from a computer to a peripheral device; A download is any file that is offered for downloading or that has been downloaded.

Drive-by download

When programs are downloaded without the user's knowledge or consent. Most often accomplished when the user clicks to close or eliminate a random advertisement or other dialogue box.


The scrambling of data so it becomes difficult to unscramble and interpret.

File Sharing

The practice of making files available for other users to download over the Internet and smaller networks. Usually file sharing follows the peer-to-peer (P2P) model, where the files are stored on and served by personal computers of the users.


Prevents computers on a network from communicating directly with external computer systems. A firewall typically consists of a computer that acts as a barrier through which all information passing between the networks and the external systems must travel. The firewall software analyzes information passing between the two and rejects it if it does not conform to pre-configured rules. Firewalls provide effective protection against worm infection, but not against spyware like Trojans, which hide in legitimate applications, then install secretly on a user's PC when the application is launched.


Software installed with completely unrelated programs. Developers of shareware or freeware with large distribution sometimes get paid to bundle unrelated software with their software. The foistware in most cases is mentioned in the End User License Agreement.


A programmer who breaks into computer systems in order to steal or change or destroy information as a form of cyber-terrorism.

Homepage hijacker

Sometimes called browser hijackers, homepage hijackers can change your default home page as well as other Web browser settings. Common behavior also includes adding advertising, pornographic, or other unwanted bookmarks, creating pop-up advertisements, and redirecting mistyped or incomplete URLs. Additionally, home page hijackers may redirect your searches to "pay-per-search" Web sites.


Invented by Netscape to provide authentication and encrypted communication, https is widely used for security-sensitive online communication such as payment transactions and corporate logons. Https refers to the combination of a normal HTTP interaction over an encrypted Secure Sockets Layer (SSL) or Transport Layer Security (TLS) transport mechanism.

Identity theft

The criminal abuse of consumers' personal identifiers. The main concern for consumers is financial crime exploiting their credit worthiness to commit loan fraud, mortgage fraud, lines-of-credit fraud, credit card fraud, commodities and services frauds.

Information privacy

The interest an individual has in controlling, or at least significantly influencing, the handling of data about themselves.


Internet Service Provider (ISP, also called Internet access provider or IAP). A business or organization that sells to consumers access to the Internet and related services. In the past, most ISPs were run by the phone companies. Now, ISPs can be started by just about any individual or group with sufficient money and expertise. In addition to Internet access via various technologies such as dial-up and DSL, they may provide a combination of services including Internet transit, domain name registration and hosting, web hosting, and colocation.

Instant messaging

A form of real-time communication between two or more people based on typed text. The text is conveyed via computers connected over a network such as the Internet.


A type of system monitor that has the ability to record all keystrokes on your computer. Therefore, a keylogger can record and log your email conversations, chat room conversations, instant messages, and any other typed material. They have the ability to run in the background, hiding their presence.

Layer Socket Provider (LSP)

A system driver that is linked into the Networking system for Microsoft Windows computers. It has the ability to access all data entering and leaving through the network interfaces.

Malicious software

Software designed to infiltrate or damage a computer system without the owner's informed consent. Also known as malware.


Software designed to infiltrate or damage a computer system without the owner's informed consent. Also known as malicious software.


A social networking Web site offering an interactive, user-submitted network of friends, personal profiles, blogs, groups, photos, music and videos. MySpace also features an internal search engine and an internal email system.

Operating system

The underlying software that enables you to interact with the computer. The operating system controls the computer storage, communications and task management functions. Examples of common operating stems include: MS-DOS, MacOS, Linux, Windows. Also: OS, DOS.

PC crashes

A computer program (either an application or part of the operating system) stops performing its expected function and stops responding to other parts of the system. Often the offending program may simply appear to freeze.

Personally Identifiable Information (PII)

Information such as name, address, phone number, credit card information, bank account information, or social security number.


Webroot's Phileas is  the industry's first and only automated spyware research system. Phileas consists of dozens of servers arrayed in a data center. Each server hosts one or more "bots" that scour the Web for Web sites that contain spyware.

Bots search each site, revealing pages with characteristics of exploits or suspicious application code or suspected new spyware threats. Innovative, pattern-matching technologies allow Phileas to identify known and unknown exploits, plus any changes to existing spyware variants. New URL targets identified by Phileas are sent to Webroot for processing and evaluation.

The Webroot Threat Research team uses proprietary algorithms to create definitions for each new spyware signature or variant, which go through an extensive quality assurance process before being released to customers.


A criminal activity using social engineering techniques. Phishers attempt to fraudulently acquire sensitive information, such as passwords and credit card details, by masquerading as a trustworthy person or business in an electronic communication. Phishing is typically carried out using email or instant messaging.


A personal identification number (PIN) is a secret numeric password shared between a user and a system that can be used to authenticate the user to the system. Typically, the user is required to provide a non-confidential user identifier or token (such as a banking card) and a confidential PIN to gain access to the system. Upon receiving the User ID and PIN, the system looks up the PIN based upon the User ID and compares the looked-up PIN with the received PIN. Only if they match is the user granted access.


A tool used to see if a computer is operating and to see if network connections are functioning. Essentially when someone performs a "Ping" they are sending packets of information out to a specific host and are waiting to see when or if they get a response.  This function is used to see if you can reach another computer and to see how it takes to get information "bounced back".


A form of online advertising intended to increase Web traffic or capture email addresses. It works when certain websites open a new browser window to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well.


One that victimizes, plunders, or destroys, especially for one's own gain.


The interest that individuals have in sustaining a 'personal space,' free from interference by other people and organizations.

Privacy policy

The responsibilities of the organization that is collecting personal information and the rights of the individual who provided the personal information. Typically, this means that an organization will explain why information is being collected, how it will be used, and what steps will be taken to limit improper disclosure. It also means that individuals will be able to obtain their own data and make corrections if necessary.

"remove me"

An option within spam that is often false.  That is, if you click a "remove me" link within a spam message you very well may be subjecting yourself to more spam, because by responding, the sender knows that your email account is active. A 2002 study performed by the FTC demonstrated that in 63% of the cases where a spam offered a "remove me" option, responding either did nothing or resulted in more email.


A set of software tools intended to conceal running processes, files or system data from the operating system; Used increasingly by malware to help intruders maintain access to systems while avoiding detection.


Software distributed for evaluation without cost, but that requires payment to the author for full rights. If, after trying the software, you do not intend to use it, you simply delete it. Using unregistered shareware beyond the evaluation period is pirating.

Slow PC

Sluggish performance of vital computer programs, like operating system or Internet browser. Usually caused by spyware infection that consumes a substantial amount of computer memory, leaving limited resources for other legitimate programs to use.

Social networking

Social software specifically focused on the building and verifying of online social networks for whatever purpose. Many social networking services are also blog hosting services. As of 2005, there are over three hundred known social networking websites. mySpace and Facebook are some examples.


A global leader in the fight against computer viruses.


Spam is unsolicited commercial email. It is sent, usually in bulk, through "open-relays" to millions of people. Spam is cost-shifted advertising. It takes a toll on Internet users' time, their resources, and the resources of Internet Service Providers (ISP). Most recently, spammers have begun to send advertisements via text message to cell phones.


Spyware is any application that makes potentially unwanted changes to your computer while collecting information about your computer activities. This information may then be sent to a third party for malicious purposes, without your knowledge or consent. Spyware arrives bundled with freeware or shareware, through email or instant messenger, as an ActiveX installation, or by someone with access to your computer. Unlike traditional personalization or session cookies, spyware is difficult to detect, and difficult (if not impossible) for the average user to remove without the use of a top-quality anti-spyware program.


Secure Sockets Layer (SSL), are cryptographic protocols which provide secure communications on the Internet for such things as Web browsing, email, Internet faxing, and other data transfers.  SSL allows client/server applications to communicate in a way designed to prevent eavesdropping, tampering, and message forgery.

System monitor

A type of spyware that has the ability to monitor all of your computer activity. They range in capabilities and may record some or all of the following: keystrokes, emails, chat room conversations, instant messages, Web sites visited, programs run, time spent, and even usernames and passwords. The information is gathered via remote access or sent by email, and may then be stored for later retrieval.

Trojan horse

A malicious program that allows a hacker to make changes to your computer. Unlike a virus, a Trojan does not replicate itself. It is generally disguised as a harmless software program and distributed as an email attachment. Once you open the attachment, the Trojan may install itself on your computer without your knowledge or consent. It has the ability to manage files on your computer, including creating, deleting, renaming, viewing, or transferring files to or from your computer. It may utilize a program manager that allows a hacker to install, execute, open, or close software programs. The hacker may have the ability to open and close your CD-ROM drive, gain control of your cursor and keyboard, and may even send spam by sending mass emails from your infected computer. They have the ability to run in the background, hiding their presence.


A Virus is a computer program which distributes copies of itself, even without permission or knowledge of the user.  Though the term is commonly used to refer to a range of malware, a true virus must do these two things: self replicate and execute itself.


In computer security, the word vulnerability refers to a weakness in a system or PC that allows an attacker to violate the confidentiality, integrity or availability of a system or PC.


A program that replicates itself over a computer network and usually performs malicious actions, such as using up the computer's resources and possibly shutting the system down. The name is an acronym for "write once, read many." A recent example of a worm is the Sasser worm (or W32.Sasser.A and its variants) that affected millions of corporate and private computer systems. Earlier in 2004, the Netsky worm (or W32/Netsky) spread by mass email using addresses obtained from an infected computer. It also spreads via local networks by trying to copy itself to shared folders on drives C: to Z: