Cisco IOS Router Exploitation - Selective Redirection

 One of the more trivial uses of a compromised router is to selectively redirect clients that attempt to communicate with a specific IP address or range. This is part of the core functionality of a router and therefore does not pose any problems to the attacker, while being relatively hard to identify for the network engineer when not done by configuration changes.

Selective redirection is known9 to be a simple and effective tool to prevent regular users from using web sites and services with encryption (HTTPS), as most users first hit the unencrypted HTTP port and expect to be redirected but fail to recognize when that's not the case.