One or more MSRP data packets are received from a first MSRP session and creates a first log entry. One or more MSRP data packets are also received from a second MSRP session and create a second log entry. A correlation between the first and second MSRP sessions based on MDNs can be detected, and mapped correlating information to malicious activity. The mapping includes reconstructing MSRP messages sent from a source and encapsulated in a data field of the packets, including MDNs, and matching to at least one threat from a malicious activity database. In response to the threat matching, to conduct a security action on the first and second MSRP sessions.