| Vulnerabilities allow breaches in security to occur. Allowing drinks around PCs; if spilled on the PC, liquid can cause a short circuit. Out of date virus protection; the chances of an obtaining a virus are multiplied with out-of-date software. A casual attitude toward security; many breaches occur because people ignore the warning signs. Cisco's NetSonar" is an assessment tool used to scan networks for vulnerabilities. Scan your network on a periodic basis, since there are new threats discovered every day.