Many vulnerabilities and malicious viruses enter the network via employees’ e-mail activities. Anti-virus software must be used on all systems commonly affected by viruses to protect systems from malicious software.

Unscrupulous individuals use security vulnerabilities to gain privileged access to systems. Many of these vulnerabilities are fixed by vendor-provided security patches. All systems must have the most recently released, appropriate software patches to protect against exploitation by employees, external hackers, and viruses. Note: Appropriate software patches are those patches that have been evaluated and tested sufficiently to determine that the patches do not conflict with existing security configurations. For in-house developed applications, numerous vulnerabilities can be avoided by using standard system development processes and secure coding techniques.