Abstract: An Account Takeover (ATO) threat detection system is configured to detect that a group of IP addresses is a suspected group of IP addresses (in that there is an indication that same potentially malicious entity is using a group of IP addresses to attempt logins) and automatically select a lower value that limits how many login attempts from the same IP address are permitted during a predetermined period of time before a login request from the suspected group of IP address is no longer accepted for processing. The limit that is used to restrict login attempts from a single IP address is set to be lower than a solo threshold value.

Abstract: An Account Takeover (ATO) detection system is configured to generate a visualization of the monitored login attempts during a time period with respect to an on-line service. In the visualization, a login attempt from an IP address is presented as an object in a three-dimensional coordinates system. This three-dimensional coordinates system has the first axis representing the first octet of an IP address, the second axis representing the second octet of an IP address, and the third axis representing the third and the fourth octets of the IP address.