Practical Malware Analysis

Network Countermeasures

Basic attributes of network activity—such as IP addresses, TCP and UDP ports, domain names, and traffic content—are used by networking and security devices to provide defenses. Firewalls and routers can be used to restrict access to a network based on IP addresses and ports. DNS servers can be configured to reroute known malicious domains to an internal host, known as a sinkhole. Proxy servers can be configured to detect or prevent access to specific domains.

Intrusion detection systems (IDSs), intrusion prevention systems (IPSs), and other security appliances, such as email and web proxies, make it possible to employ content-based countermeasures. Content-based defense systems allow for deeper inspection of traffic, and ...