The person who achieves unauthorized access to the computer system or tries to achieve it is called intruder.
Types of intruders:- There are three classes of intruders:
Mascherder: A person who is not authorized to use a computer, but infiltrates the system and exploits a valid user account.
Current: The person who is authorized for access but misuses his privileges.
Secret User: A person who takes the supervisory control of the system in his hand and uses this control for entry control. The intruding identification system (ID) is used to detect unauthorized infiltration in computer systems and networks.
Fishing
The task of sending an email to a user to be an established legitimate venture, which aims to cheat to hand over personal information to the user and use it for theft of identity. The email instructs the user to visit a web site where they are asked to update personal information like password, credit card details, social security and bank account number. However, this website is fake and has been established only to steal the user information.
Fishing attacks are also used to steal your money !!!
Fishing scams can occur-
An email inviting you to join a social group, in which you are asked to login using your user name and password.
Explain in email that your bank account is locked and sign in to your account to unlock it.
Email that has some information about your interest and you have been asked to login to your account. Any email that has a link to click and asked you to login.
A link for attractive events, news, photos, videos and presentation that tells for a safe login.