• PC World
• »Software
• »Antivirus and Security

Strategy: Defense in Depth

Layers of protection block different kinds of threats and may provide backup if one layer fails.

Hardware router

• Using NAT¹ masks IP address from port scans.
• Blocks unsolicited incoming communications.
• Does not protect against most malware, such as Trojan horses, viruses, e-mail worms, and spyware.

Software firewall

• Prevents backdoor apps, Trojan horses, and unwanted applications from sending data from the PC.
• Protects a laptop on public wired and wireless networks.
• Can block some malware, but can't remove it.

Antispam software

• Blocks deceptive e-mail scams (phishing schemes).
• Reduces e-mail sorting fatigue, so users are less likely to accidentally activate an e-mail-borne virus in haste.

Antivirus software

• Protects against known worms, viruses, and Trojan horses but is less effective against new infectors.
• Systems are still vulnerable to infiltration from adware, spyware, and browser hijackers.

Anti-spyware software

• Protects against adware, browser hijackers, spyware, tracking cookies, and other Internet parasites.

¹The Network Address Translation Internet standard allows LANs to use different sets of IP addresses for internal and external traffic.