#Search for Rogue Listeners
Purpose: Find malicious programs that are listening to network ports
Data Required: Netstat data (netstat -nabo) or equivalent from local host
Collection Considerations: Requires some sort of agent to collect this data on a regular basis
Analysis Techniques: Stack counting
Extract src & dest host/port fields from all netstat data, as well as the full path name for the associated executable. Look for:
- More than one process name bound to the same port on the same system (the ones with the smallest number of occurrences on each system are suspicious)
- For all Internet-accessible servers, which ports show up only once (or just a few times)?
- For all Internet-accessible servers, how many binaries show up only once (or just a few times)?
- Track new listeners over time for each system, use this as a baseline to refine future hunts.
- Intrusion Hunting for the Masses, David Sharpe (HackMiami 2016)