1. Spam : Distribute unwanted e – mail to a large number of internet users.
2. Fraud : Manipulating data, for example changing the banking records to transfer money to an unauthorized account.
3. Cyber stalking : Harassing through online.
4. Spoofing : It is a malicious practice in which communication is send from unknown source disguised as a source known to the receiver.
5. Virus : A virus is a small piece of computer code that can repeat itself and spreads from one computer to another by attaching itself to another computer file. One of the most common virus is Trojan.
6. Worms : Worms are self – repeating and do not require a computer program to attach themselves. Worms continually look for vulnerabilities and report back to the author of the worm when weaknesses are discovered.