In the case of the sample described in the post, there was a TLS handshake that was immediately terminated, followed by a client hello and the heartbeats. The c

In the case of the sample described in the post, there was a TLS handshake that was immediately terminated, followed by a client hello and the heartbeats. The client hello and heartbeats were sent in the clear. I conjecture that the TLS handshake was used to fingerprint the server, since not all 3 versions of the payload will succeed on all TLS versions.