Because malware is so prevalent, it’s important to protect systems. The primary method of protection is antivirus software and an aggressive defense-in-depth strategy. As an overview, the following methods can be implemented as countermeasures against malware:
• Install antivirus software on all systems.
• Install antivirus and antispam software on e-mail servers.
• Install antivirus and content filter software on firewalls.
• Keep all antivirus software up to date.
• Keep all systems up to date.
• Educate users.
Figure 6-1 shows a popular multipronged approach to installing AV software. First, content-filtering firewalls are placed between the Internet and the internal network to filter all traffic ...