Scumware, also known as parasiteware or spyware, is software that users unknowingly download when it piggybacks with another program that you're intentionally downloading. Some examples of the programs that contain the hidden spyware are Gator, Bonzi, Kazaa, Morpheus, Weather.net - for a full listing see Spyware Guide.com . Gator is so invasive that even after you remove the program it will leave a file designed to "trickle" down Gator files back onto your computer, so that within a few days you'll have the full Gator program back on your computer, even though you've removed it.

Most of the scumware/parasiteware/spyware products are installed on your computer by companies that want to track your internet usage and use that information. The software watches and records where you go on the internet and transmits your personal data back to those companies for advertising purposes. Once they know what it is you like, they start serving popup ads to you, tailored to fit your usage.

FYI. How about 寄生废物软件. I think it will get the meaning out. It is a parasite, which is useless.

From Scumware.com:

What does Scumware mean Anyways?

FAQ: Scumware, Spyware, Adware and Malware definitions

--------------------------------------------------------------------------------

what does 'Scumware' mean anyways?
Sometimes its easier to understand the concepts behind these types of programs, so here is a mini-reference with definitions which describe how each type of software works and how it is commonly used.

Scumware: Software, scripts or programs that are specifically designed to circumvent or steal revenue and traffic from legitimate web sites. Most scumware is also considered to be spyware since it usually includes programs which transmit your personal information. Scumware is usually installed without consent and bundled with other programs such as popular filesharing programs or Adware.

Spyware: Software components that are usually downloaded for free from the internet and installed with products that send information from the user's computer without their knowledge or consent. Although it is predominantly found in shareware, spyware can also be found in legitimately purchased commercial software that collects personal information from your computer. It is generally considered to consist primarily of 'stealth' components and background processes that may violate your privacy and/or expose your personal information and your computer to attack. Usually the information sent is benign in nature, mostly concerned with general marketing information (ie., spending habits) rather than specific information like credit card numbers, although some programs are capable of retrieving specific information as well. Spyware does not respect privacy as information is transmitted without consent.

Adware: Adware is advertising supported software. It can be downloaded free from the web but carries banner advertisements or links that attempt to create revenue for the company. It usually installs components on your computer that transmit marketing information to central servers which in some programs is then used to tailor the advertising presented for increased effectiveness. The main difference between Adware and Spyware is that Adware usually contains a disclosure which reveals exactly which information is being collected and how it is used.

Malware: This term has been shortened from "malicious software" and is usually applied to cover a wide range of 'hostile' software such as Viruses, Trojan Horses and Worms. It is software that is designed specifically to damage or disrupt a system, files or its components.

======
Scumware

Scumware - software which places active ads in response to your searches or the web sites you visit without you or the web site asking for it. The GAIN corporation creates scumware. Some other companies produce similar scumware which they claim to "not be scumware" If it is annoying and ruining your web experience then it doesn't matter if they call it scumware or not.

Usually scumware comes in a package deal with some other software like a stupid clock. Frequently these programs are as hard to get rid of as AOL. I recommend using AdAware if you get any scumware stuck on your computer as it has stopped my scumware problems dead in their tracks. AdAware is a free scumware removal software program.
==============
scumware






Scumware is any programming that gets on your computer from Internet sites without your consent and often without your knowledge. Scumware is a general term that encompasses spyware, adware, annoyware, malware, parasiteware, unwelcome cookies, and various forms of viruses.
Scumware has become an increasing problem in recent years. Tactics employed by scumware purveyors range from deception to fraud to outright larceny. Scumware can arrive as part of some shareware and freeware packages. Scumware can also be used to facilitate identity theft. A number of programs are available to limit the vulnerability of computers to scumware. They include firewalls, anti-virus software, pop-up ad blockers, and programs designed to detect and delete cookies and spyware.
=============

根據我搜尋的結果，有時候scumware是專指那些盜用、改變身分，也就是一般說的變臉軟體。但很多情況下，scumware也用來通稱所有的spyware, adware, malware。