Check egress filtering and identify if ports are allowed to automatically spawn a shell.
EgressBuster is a way to test the effectiveness of egress filtering for an individual area. When performing a penetration test, often times companies leverage egress filtering in order to prevent access to the outside Internet. Most companies have special exceptions and allow ports but they may be difficult to find.
There are two components to EgressBuster:
- egressbuster - the egressbuster.py or egressbuster.exe can be run in Linux/OSX/Windows(EXE). This will check outbound ports to a location where you have egress_listener.py. Run this on the victim machine you want to check the ports on. You can also spawn an automatic command shell once a port is detected.
- egressbuster_listener.py - this is the listener, this will automatically use IPTables to listen on all 65k ports for a connection. When a connection is allowed, it will notify you as well as spawn a shell if you specified the shell option.