Be careful who you give out credentials to if you're running SMB (also known as "Microsoft Windows Network"). It might just be that this person is malicious. Let's assume we wanted to be that person in order to show what an attacker would be able to do.

Picture yourself at a LAN party or the like where somebody wanted to share data, but only to distinguished individuals. Now imagine that we are one of these people and are supplied with the username "Individual" and password "Important". This situation is plausible.

In 1996 it was discovered that the MD5 hash-algorithm had problems. Furthermore, an algorithm was devised to generate these collisions in 2005.