There are various discussions within the IT industry as to the classification of spyware, however the most common is as follows. Spyware is generally installed without your knowledge and comes from some softwares released by companies who are interested in giving you sponsored advertising or target you with various information collection systems. The information gathered is usually unsolicited and is stealthy. It also can generate increased network traffic and may conflict with home or corporate software. Spyware has the ability to

• Gather a user's private/personal information
• Steal copyrighted or confidential information
• Create irreparable system instability
• Damage or interfere with legitimate application operations
• Open a backdoor on infected systems
• Take over an infected system

The biggest risk to companies and home users alike is the fact it creates security holes which enable the uncontrolled flow of data out of an computer into the internet.

Malware

Malware, is always man made, it is designed to infiltrate and sometimes damage a target machine usually without the persons knowledge. Malware is a term used to describe a variety of hostile, intrusive, or annoying software or program code. Malware is written with an objective in mind, usually underhand or hostile to a system it is infecting.

Malware should not be confused with defective software, that is, software which has a legitimate purpose but contains harmful bugs.

Grayware

Grayware refers to various programs that can usually be regarded as undesirable. This might includes applications that can cause a load on network traffic or are inappropriate within a corporate environment.

Some Grayware can introduce security risks on to the system while others are purly malicious. Some people may refer to these applications as beneficial i.e. peer to peer applications.

Viruses, Trojans and Worms are not included under this classification but , adware, peer to peer applications as well as various browser helper objects and search redirectors are considered Grayware.