Q:

Risks of creating a user with no shell

Are there any security risks when creating a user(s) with no shell, and no special privileges (using fairly strong passwords)?
Reasons

To redirect the attackers attention from "real" users (e.g. real user "smr", fake user "admin")
Secure logging of attempts to break into the system
Better distinguishable from login attempts to real accounts

Additional: How to notify an admin of "too many" suspicious attempts / what best to do?

A:

It looks to me like a level of obscurity. In order to protect your admin account, the recommended way is to have a strong password, or even better an asymetric key on SSH. You can in addition provide a honey pot login named admin, but it does not add a lot of security, nor avoid logs examinations for real logins. IMHO, it would be mainly interesting if you were studying the behaviour of attackers, because no normal login attemps should occur on the honeypot.
As usually for obscurity, nothing is wrong if you do not rely on it but only see it as an additional protection level.

