From Paul Gil, Your Guide to Internet for Beginners.
How Rogue Software Hurts Us All
1) What is “Spyware”?
Forget viruses, spam and hacker attacks..."spyware" is now the single largest problem facing internet users today. These nasty little rogue programs have become so widespread and so infectious, their volume far outstrips spam and regular viruses. The spyware problem has grown to such an immense breadth and depth, we cannot even agree on what to call it.
2) Spyware = 'Malware' Most people historically call these rogue programs "spyware".
That name comes from the 1990's where nasty little programs secretly observed and logged your web surfing habits. The spyware problem, however, has now grown into dozens of other malicious formats, including sneakware, adware, keyloggers, browser hijackers, porn servers, trojans and worms Because the spyware problem has mutated so much, we now describe spyware as part of a much larger category of rogue software called "malware" (malicious software programs). At its most basic definition, malware is when insidious little software programs covertly install themselves on your computer, and then perform secret operations without your permission. Once in place, malware programs may do hundreds of nasty things to your computer. Malware will log your keystrokes, steal your passwords, observe your browsing choices, spawn pop-up windows, send you targeted email, redirect your web browser to phishing pages, report your personal information to distant servers, and serve up pornography. This malware will operate invisibly, often without displaying itself in your Task Manager. To top it off, malware usually refuses to be uninstalled through your control panel, and requires special tools to delete them from your drive. Yes, this is a direct cousin to viruses, but with a broader portfolio of wicked intentions.
3) What does Spyware/Malware specifically do to my computer?
Malware will perform a variety of nasty activities, ranging from simple email advertising all the way to complex identity-theft and password-stealing. New nasty functions are created every week by malware programmers, but the most common malware functions are:
1. Malware steals your personal information and address book (identity theft and keystroke-logging). 2. Malware floods your browser with pop-up advertising.
3. Malware spams your inbox with advertising email.
4. Malware slows down your connection.
5. Malware hijacks your browser and redirects you to an advertising or a phishing-con web page.
6. Malware uses your computer as a secret server to broadcast pornography files.
7. Malware slows down or crashes your computer.
4) Where does Spyware/Malware come from?
Spyware/malware programs are authored by clever programmers, and then delivered to your computer through covert Internet installs. Usually, malware will piggyback on innocent-looking web page components and otherwise-benign software such as game demos, MP3 players, search toolbars, software, free subscriptions, and other things you download from the web. Subscribing to online services is especially bad for getting malware. In particular, whenever you sign up for a so-called "free" service or install new software, you must accept an "end user license agreement" (EULA). The fine print of the EULA will often include the phrase "the vendor is allowed to install third-party software on your computer". Since most users don't bother to read this EULA fine print, they naively click "accept", and install malware out of sheer ignorance.
5) What kind of personal information does Spyware/Malware steal?
This varies from the non-confidential to the extremely-personal. The malware may simply steal a listing of your MP3s or recent website visits. Malware may also harvest your email address book. At its very worst, malware will steal your banking PIN, your eBay login, and your Paypal information (aka "keystroke logging" identity theft). Yes, spyware/malware is a very serious Internet problem that threatens everyone's personal privacy, and network administrators everywhere are deeply concerned.
*** From: http://netforbeginners.about.com/od/antivirusantispyware/a/malware101.htm
