This is a mod which applies random Curse enchantments at three random times from midnight to 3am in-game. These times are resettet each day. The chance is configurable in the server config. To prevent this, you simply need to sleep. The mod needs to be on client and server. If the mod is only on server, the client will only see the unlocalized message.
It is highly recommended to use this mod with other mods which add curse enchantments
You're allowed to use this mod in any modpack.