1. Viruses, Computer Security & Ethical Issues Digital Communication Systems Ms. Powers

2. What software can I copy? Software can be classified as: –Public domain - is donated for public use making it free to everyone. It can also be copied freely because it is not copyrighted. –Shareware - is distributed on a trial basis by the author who retains the copyright making it copyright protected. It may expire after the trial period and not allow a reinstall until a small fee is paid and you register the software. –Freeware - is given away free of charge, but the author still retains the copyright. The program cannot be sold or altered without permission and it is not necessarily free to copy and distribute.

3. What software can I copy? Software can also be classified as: –Copyrighted software - includes programs sold with accompanying documentation, user support and an owner ’ s manual. You cannot copy these, except for backup purposes if that is permissible. –Commercial Software - is considered proprietary software and is copyrighted by an individual or business. It is usually disabled after a specified number of uses and needs permission in order to be copied. Piracy is the illegal copying and distribution of software. Copyright is protection giving the owner the exclusive rights to reproduce or distribute copies of his or her own work.

4. Major types of Viruses Virus –Software/computer program written to cause damage to or destroy computer files. Example: The Melissa virus was a self-replicating macro virus that reactivated each time the next user opened a Word e-mail attachment. It stopped the flow of activity on the Internet due to the volume of e-mail it generated but did not damage individual systems. Bomb –Activates on a particular date or specific time. Example: The Michelangelo bomb activated on the artist ’ s birthday, March 6, in 1994. It was spread by infected floppy disks.

5. Major Types of Viruses Trojan Horse –A program disguised to perform a useful function but instead performs undisclosed malicious functions. They infiltrate a computer and often enter a network illegally. Worm –A program designed to enter a network (like a worm boring into an apple), reproduce and spread. Example: The Internet Worm created by Robert Morris Jr. in 1988 did not change or delete any files but did bring down over 6000 systems.

6. Major Types of Viruses Hoax –is a program intended to scare users into thinking they have a virus. Phage –is a program that modifies other programs, operating systems, and databases.

7. Computer Threats Viruses can be transmitted through a bulletin board or on-line service. You can infect your computer without knowing it by downloading a file containing a virus. Diskettes can copy a virus from the diskette to the hard drive and every other diskette used in that machine. A hacker which is a person who secretly gains access to computers and files without permission. File Sharing on a local network (LAN) may also expose your files to a virus.

8. Security Measures Protect your data with current anti-virus software. –These programs detect viruses and repair files. Backup your data regularly and store on a separate storage media. Password protect your computer files and do not use common names. Instead use a combination of text, numbers, and symbols for passwords. Use encryption for confidential material. –Encryption is a process that converts data into an indecipherable code to protect sensitive information from transferring; only the sender and receiver can read it. Restrict access to networks by requiring a user name and password, limiting number of log-in retries, force a log-off and require frequent password changes.