Is it possible to decrypt MD5 hashes?

Question

Someone told me that he has seen software systems that:

1. retrieve MD5 encrypted passwords from other systems;
2. decrypt the encrypted passwords and

Answer 1

Decryption (directly getting the the plain text from the hashed value, in an algorithmic way), no.

There are, however, methods that use what is known as a rainbow table. It is pretty feasible if your passwords are hashed without a salt.