Spyware is hardly noticeable as it is usually bundled together with other free-wares such as screen savers, image editing tools, smiley icons, etc.
When someone did not realize downloading the spyware. It can also be downloaded when the person is tricked into downloading a dangerous email attachment or when he/she visits a website that is infected with malicious codes. The programme then collects personal information, such as credit card numbers and bank account numbers. This information will be sent to cybercriminals who uses it to steal a person’s identity.