All-in-One Cambridge Dictionary

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Risk likelihood measures the probability that a Chrome extension may turn malicious. This is determined by the publisher and the Chrome extension reputation on Chrome Web Store, the amount of time the Chrome extension has been around, and other signals about the Chrome extension. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Chrome extension.