I wouldn't expect it to be less murderous than the aliens themselves. That wasn't my point at all. I'd expect it to contain all their knowledge and be able to live "forever".
But I generally wouldn't expect aliens to be "murderous" at all. Why send a group or probe lightyears away just to kill or enslave a primitive species? If they have the ability to do that, we wouldn't really have anything of interest for them.
At most points in time resources are scarce and not all life can be supported. At those times beings with a tendency to say “them” will give way to beings who most strongly assert “us”.
The scarcity view of life is so deeply ingrained in some of us that its become an entire world view. Some folks cant even imagine a post scarcity society.
Try though. Space is mind blowingly large and anything with the ability to traverse interstellar space alteady has access to unlimited resources and energy, likely closer than us. We live in a tiny backwater of the galaxy.
We literally have nothing of value to such a civilization. Gold and diamonds a just more rocks to any serious space faring civilizations. Energy is also unlimited and free.
Unless they find us delicious our only value would likely be an exchange of knowledge.