A malware detection and response system based on traffic pattern anomalies detection is provided, whereby packets associated with a variety of protocols on each port of a network element are counted distinctly for each direction. Such packets include: ARP requests, TCP/SYN requests and acknowledgements, TCP/RST packets, DNS/NETBEUI name lookups, out-going ICMP packets, UDP packets, etc. When a packet causes an individual count or combination of counts to exceed a threshold, appropriate action is taken. The system can be incorporated into the fast path, that is, the data plane, enabling communications systems such as switches, routers, and DSLAMs to have built-in security at a very low cost.