Bitter Harvest: Systematically Fingerprinting Low- and Medium-interaction Honeypots at Internet Scale

The current generation of low- and medium interaction honeypots uses off-the-shelf libraries to provide the transport layer. We show that this architecture is fatally flawed because the protocols are implemented subtly differently from the systems being impersonated. We present a generic technique for systematically fingerprinting low- and medium interaction honeypots at Internet scale with just one packet and an ERR (Equal Error Rate) of 0.0183. We conduct Internet-wide scans and identify 7,605 honeypot instances across nine different honeypot implementations for the most important network protocols SSH, Telnet, and HTTP. For SSH honeypots we also determined their patch level and find that they are poorly maintained -- 27% of the honeypots have not been updated within the last 31 months and only 39% incorporate improvements from 7 months ago. We believe our findings to be a `class break' in that trivial patches cannot address the issue.