MGX Gui

An MGX Gui (short for Maintenance GUI) is a GUI that a Roblox user adds to their own game. The purpose of an MGX Gui is to phish somebody else's account password. Many times they are in the form of a Maintenance GUI that asks for the victim's password. They are currently on the rise as Roblox removed comments from avatar items made by Roblox and games to stop the spread of phishing sites. They use Discord webhooks and Youtube vids to get the gui and maybe they use discord servers the get the mgui.

MGX7
An MGX7 is an MGX GUI that is injected into other users' experience servers using a level 7 exploit instead of being inserted into their own experience through Roblox Studio. These GUIs are considered more "dangerous" as they can easily target more people.

Staying safe
You shouldn't fall for these scams and enter your password as this won't give the promised items to your account. Getting scammed from MGX GUI's is very easy as all you have to do is enter your password. Many versions of MGX GUI's threaten to kick you out of the game after a set time or to permanently ban you. However, there is no reason to be scared because the worst they can do is trello ban you out of a server. To avoid being kicked out, you can enter a fake password to make the GUI disappear, but most of these GUIs have now been updated with a password checker so they are more convincing, but you shouldn't fall for any login gui in a Roblox game. If you do fall for one of these scams, change your password ASAP. The scammer won't be able to get into the account.