It can easily infect the system memory, partition table, boot sector, executable files and system files. Tradition shows most viruses are spread unknowingly by using contaminated diskettes or by downloading contaminated programs or data from networked systems. With stand-alone computers, infection can happen only by using contaminated diskettes. In networks, most file virus contamination can spread in a matter of seconds. Available disk space decreases rapidly.
Files disappear mysteriously or programs encounter unusual messages.
Immediately stop work on the system, isolate and contain all diskettes in the area. Ensure others do not use your computer. If they are not available, contact your Installation's computer security manager or the help desk. The best way to protect a computer is to use anti-virus software, make backups and use good computer security practices. Backups of programs and operating files should be made regularly.