| 1.2 |  | Vulnerabilities and Threats |
| 1.2.2 |  | Primary network threats |

| There are four primary classes of threats to network security :

1. Unstructured threats
   Unstructured threats consist of mostly inexperienced individuals using easily available hacking tools such as shell scripts and password crackers . Even unstructured threats that are only executed with the intent of testing and challenging a hacker’s skills can still do serious damage to a company. For example, if an external company Web site is hacked, the integrity of the company is damaged. Even if the external Web site is separate from the internal information that sits behind a protective firewall, the public does not know that. All the public knows is that the site is not a safe environment to conduct business.
2. Structured threats
   Structured threats come from hackers that are more highly motivated and technically competent . These people know system vulnerabilities, and can understand and develop exploit-code and scripts. They understand, develop, and use sophisticated hacking techniques to penetrate unsuspecting businesses. These groups are often involved with the major fraud and theft cases reported to law enforcement agencies.
3. External threats
   External threats can arise from individuals or organizations working outside of a company. They do not have authorized access to the computer systems or network. They work their way into a network mainly from the Internet or dialup access servers.
4. Internal threats
   Internal threats occur when someone has authorized access to the network with either an account on a server or physical access to the network. According to the FBI, internal access and misuse account for 60 to 80 percent of reported incidents.

| Web Links Vulnerability Statistics Report http://www.cisco.com/warp/public/778/ security/vuln_stats_02-03-00.html Incident Response
http://www.cisco.com/warp/public/707/
sec_incident_response.shtml