[B]Grayware[/B] (or greyware) is a general classification for applications that behave in a manner that is annoying or undesirable. Grayware encompasses spyware, adware, dialers, joke programs, remote access tools, and any other unwelcome files and programs apart from viruses that can harm the performance of computers on your network. The term has been in use since at least as early as September 2004.
Grayware refers to applications or files that are not classified as viruses or trojan horse programs, but can still negatively affect the performance of the computers on your network and introduce significant security risks to your organization. Often grayware performs a variety of undesired and threatening actions such as irritating users with pop-up windows, logging user key strokes, and exposing computer vulnerabilities to attack.
[B]Spyware[/B] is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user’s interaction with the computer, without the user’s informed consent.
While the term spyware suggests software that secretly monitors the user’s behavior, the functions of spyware extend well beyond simple monitoring. Spyware programs can collect various types of personal information, but can also interfere with user control of the computer in other ways, such as installing additional software, redirecting Web browser activity, accessing websites blindly that will cause more harmful viruses, or diverting advertising revenue to a third party. Spyware can even change computer settings, resulting in slow connection speeds, different home pages, and loss of Internet or other programs. In an attempt to increase the understanding of spyware, a more formal classification of its included software types is captured under the term privacy-invasive software.
In response to the emergence of spyware, a small industry has sprung up dealing in anti-spyware software. Running anti-spyware software has become a widely recognized element of computer security best practices for Microsoft Windows desktop computers. A number of jurisdictions have passed anti-spyware laws, which usually target any software that is surreptitiously installed to control a user’s computer.
[B]Malware[/B] is software designed to infiltrate or damage a computer system without the owner’s informed consent. It is a portmanteau of the words “malicious” and “software”. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code.
Many normal computer users are however still unfamiliar with the term, and most never use it. Instead, “computer virus” is used in common parlance and often in the general media to describe all kinds of malware, though not all malware is a virus. Another term that has been recently coined for malware is badware, perhaps due to the anti-malware initiative Stopbadware.
Software is considered malware based on the perceived intent of the creator rather than any particular features. It includes computer viruses, worms, trojan horses, most rootkits, spyware, dishonest adware, and other malicious and unwanted software. In law, malware is sometimes known as a computer contaminant, for instance in the legal codes of California, West Virginia, and several other American states.
Malware should not be confused with defective software, that is, software which has a legitimate purpose but contains harmful bugs.
[B]Adware[/B] is software that displays advertising banners on Web browsers such as Internet Explorer and Mozilla. While not categorized as malware, many users consider adware invasive. Adware programs often create unwanted effects on a system, such as annoying popup ads and the general degradation in either network connection or system performance. Adware programs are typically installed as separate programs that are bundled with certain free software. Many users inadvertently agree to installing adware by accepting the End User License Agreement (EULA) on the free software. Adware are also often installed in tandem with spyware programs. Both programs feed off of each other’s functionalities - spyware programs profile users’ Internet behavior, while adware programs display targeted ads that correspond to the gathered user profile.
It is always advisable to have one main virus program, but periodically scan your system with other virus programs to catch things that are missed. Understand the differences between true and false positives. This holds true for Grayware as well.
There is nothing wrong with Panda Anitvirus 2008 it will do you fine. But like I said use other virus programs periodically to scan your system. I would highly recommend using Spybot-S&D as a scanner for grayware.
Spybot-S&D - http://www.safer-networking.org/en/home/index.html