Any original work is automatically copyrighted, no need for an explicit disclaimer to state such a copyright.
Without the original authors permission you are allowed to:
- Create (or have someone create) a new modification based on the same idea. It is not allowed to re-use the coding without permission.
- Modify (or have someone do this) the existing modification or your own needs. You are not allowed to redistribute such a modified version without prior permission from the original author.
Is this "automatic copyright" something in other countries?
In the US it must explicitly state it is copyrighted material or pending patent. Otherwise, it's a community distribution which has been offered as open source. I would love to be able to communicate and offer money to the person/s who've developed the mod. However, there is no way as they do not respond to posts, don't have a public email address and don't accept PM's.