This document summarizes an application of Hidden Markov Models (HMMs) to analyze HTTP payloads:
1. An HMM is used to associate a probability to each sequence of bytes in an HTTP payload and obtain an overall probability for the payload.
2. Real HTTP payload data collected from various sources on the internet is used to train the HMM.
3. The trained HMM can then be used to detect anomalies in new HTTP payloads by flagging payloads with significantly different probabilities as potential attacks or malware.