Date Added: Dec 2010
Traditionally, Network Intrusion Detection Systems (NIDS) inspect packet header and payload data for malicious content. While each system is different, most NIDS perform limited analysis on network streams and network protocols. Unfortunately, current NIDS are typically susceptible to evasion through network protocol encoding, such as base64 encoding of SMTP/MIME or gzip compression of HTTP. In addition, malicious desktop application payloads (e.g., PDF documents, Flash multimedia files) are beyond the inspection capabilities of popular NIDS.