The "Push Security SaaS App MFA Method Changed" rule monitors and alerts on changes to Multi-Factor Authentication (MFA) methods associated with a SaaS application. The rule is triggered when an MFA method is altered, such as being added or removed from a user's account. It performs several tests on account logs to verify the specifics of the changes, addressing scenarios where MFA methods are completely removed, added, or remained unchanged. The rule is categorized as informative with a warning that the MFA method has undergone a shift, emphasizing security implications of such changes. Logged events include changes from a single method 'SMS' to multiple methods like 'SMS' and 'APP_OTP', indicating an increase in security complexity.