The ASC [Anti-Spyware Coalition] drafted a definition of “spyware” in August 2005. The ASC defines “spyware and other potentially unwanted technologies” as those that “impair users’ control over material changes that affect their user experience, privacy, or system security; use of their system resources, including what programs are installed on their computers; or collection, use, and distribution of their personal or otherwise sensitive information.”

“Spyware” is something of a grey area, so there’s no copy-book definition for it. However, as the name suggests, it’s often loosely defined as software that is designed to gather data from a computer and forward it to a third party without the consent or knowledge of the computer’s owner. This includes monitoring key strokes, collecting confidential information (passwords, credit card numbers, PIN numbers, etc.), harvesting e-mail addresses, or tracking browsing habits. There’s a further by-product of spyware where such activities inevitably affect network performance, slowing down the system and thereby affecting the whole business process.

The reason “spyware” is such a grey area is that it is really just a catch-all term for a wide assortment of malware-related programs, rather than a defined category. Most “spyware” definitions apply not only to “adware”, “pornware” and “riskware” programs, but also to many Trojan programs: Backdoor Trojans, Trojan Proxies and PSW Trojans. Such programs have been around for almost 10 years, when the first AOL password stealers appeared. However, at this time the term “spyware” had not yet been used.

Another reference to spyware is “Adware”. In this case, spyware can exist in the form of malicious backdoor programs that open up ports, initiate an ftp server, or collect keystroke information and transmit it back to the attacker. Spyware can exist in the form of legal (and acceptable) commercial applications that give network administrators a great deal of power both over what they can affect, and see happening on managed systems.

Although such programs are not new, their use for malicious purposes has increased in recent years and they have received much greater attention, both from the media and from “spyware”-only vendors.