This document summarizes a research paper on detecting compromised machines that are spreading malware like worms on the internet. It presents a system called SPOT that uses Sequential Probability Ratio Testing (SPRT) to detect compromised machines. SPOT analyzes outgoing messages and IP addresses to determine if a machine is sending spam above a certain threshold. This identifies machines that are infected and using botnets to spread viruses or conduct denial of service attacks. The system was able to effectively identify compromised machines with low workload and error rates.