Contamination

Contamination may have occurred in an information system when classified information is found on a computer system which is not supposed to be there. This may have happened:

1. By accident
2. By transmission of insecure data
3. Because the information was changed to a different classification rating
4. Because users did not follow protocol and transferred information through insecure methods such as floppy disks or thumb drives

Contamination can also occur through a computer virus or other form of malware. An anti-virus tool should be enabled to remove an active virus from a system.