Spyware is a summary designation for such software that was created with the intent to gather information about the user and his behavior, or to change settings so that it is vulnerable. Spyware is installed without user’s knowledge and it often masquerades as a needed complement to other software (such as a codec). Spyware is one of moderate to serious security risks - it is harmful in that it is used to spy on users and their activities. It is therefore one of the malicious software.
The term spyware was created from the words spy and software.
How can the spyware harm?
The aim of spyware is to collect data, spy on user and then send that data to owners of spyware. They can use data to track user habits and better target advertising. In such cases, the data is anonymous and represent for the organization and users lower security risk. In severe cases, spyware can change the settings on user’s computer without their knowledge or obtain personal information of users.