PC Security

• Not just "IBM compatible microcomputers" (that is, computers running Windows 98 and similar), but any microcomputer where users sit directly at the console.

Issues:

1. These computers tend to be used by one person at a time
2. They don't have much software allowing the outside world to connect to them (via the Internet or LAN)
3. The users tend to have full control: add/remove files, change programs, change the configuration
4. In a lab, school or library environment, the same machine may be used by many people each day

Vocabulary:

Virus: a program that attaches itself to a legitimate program. It will attempt to propagate itself.

• Many viruses do no harm
• Others are very destructive
• Old style: spread by sharing floppy disks or programs based on floppy disks
• New style: spread by email attachments (or other data files)

Major threats:

1. Infection by virus. Could make the computer unusable, or could cause problems for people who use the computers, including loss of data. Solution: Active anti-virus program; "clean" system at boot time; reboot between users.
2. Change to system software. Users may make changes to anything, including deleting important system files, modifying system screen, etc. This could make a system fail to boot. Solution: Automatically "refresh" the system at boot time (e.g., from a remote server). Have backups on hand. Standardize software configurations so they are easy to put back.
3. Changes to other software. Users may add undesirable programs or content, or remove existing programs. Solution: Same as above. Also, have a clear policy on what people are allowed to do with the computers.

Home systems (or public-use systems):

• Use a virus checker regularly.
• Use a disk integrity checker (e.g., Scandisk). Better checkers (like Norton Utilities) will save critical disk information to floppy disks, which could help recover from a virus or other problem.
• Turn off automatic use of macros in office applications
• Don't run programs from unknown sources