The following are cyber attacks:
(i) Virus
(ii) Worms

"Cracking" means trying to get into computer systems in order to steal, corrupt, or illegitimately view data.

Commercial programs that are made available to the public illegally are often called warez.

An ethical issue is a problem or issue that requires a person or organization to choose between alternatives that must be evaluated as right (ethical) or wrong (unethical).
Some of the common ethical issues are listed below:
1. Cyber crime
2. Software Piracy
3. Hacking
4. Use of computers to commit fraud
5. Sabotage in the form of viruses
6. Making false claims using computers.

Generally, the following guidelines should be observed by computer users.
1. Honesty: Users should be truthful while using the internet.
2. Confidentiality: Users should not share any important information with unauthorized people.
3. Respect: Each user should respect the privacy of other users.
4. Responsibility: Each user should take ownership and responsibility for their actions.

1. Symmetric encryption is a technique to use the same key for both encryption and decryption. The main disadvantage of the symmetric key encryption is that all authorized persons involved, have to exchange the key used to encrypt the data before they can decrypt it. If anybody intercepts the key information, they may read all message.
2. The following Figure depicts the working of symmetric key encryption.

Functions of Cyber Attacks

(i) Software Piracy is "unauthorized copying of software' The following show as a diayrammatical representation of software piracy.
(ii) Most of the commercial software is licensed for use at a single computer site or for use by only one user at any time, When a user buys any software, he becomes a licensed user for that software, He is allowed to make copies of the program for backup purposes but it is against the law to distribute duplicate copies to others such illegal copying and distribution of commercial software should not be practiced
(iii) An entirely different approach to software piracy is caled shareware, acknowledges the futility of trying to stop people from copying software and instead relies on people's honesty.
(iv) Shareware publishers encourage users to give copies of programs to friends and colleagues but ask everyone who uses that program regularly to pay a registration fee to the program's author directly. Commercial programs that are made available to the public illegally are often called warez.