1. A computerized method for centrally monitoring execution of disparate computing devices for compromise via aggregation of machine data, the computing devices utilizing sensitive information, and the method being performed by one or more computer systems, wherein the computer systems are configured to access one or more electronic data sources in response to requests received from an interactive user interface, the method comprising: obtaining checkout system data associated with a plurality of checkout systems, wherein the checkout system data identifies processes executing in memory of each checkout system, and user account access information indicating user account access attempts to the checkout systems; wherein the plurality of checkout systems execute respective agents associated with monitoring, at least, processes executing in memory of the checkout systems, wherein monitored information is aggregated from the plurality of agents, and wherein a process represents code executing in an operating system of a checkout system; determining that the checkout system data identifies a first process, executing in memory of one or more compromised checkout systems, that is not known to be valid, wherein the first process represents code executing in operating systems of the one or more checkout systems; determining, using the user account access information, anomalous user behavior of a first user account, wherein determining anomalous user behavior comprises determining a speed score indicative of a measure that a single user could not travel fast enough between different locations in a period of time to access the first user account from the different locations and a location score that measures risk associated with geographic locations from which the first user account was used; generating user interface data describing the first process and the determined anomalous user behavior of the first user account; and providing at least a portion of the generated user interface data for presentation on a user device, wherein the computer systems are configured to generate time-sensitive notifications associated with compromised checkout systems and anomalous user behavior for transmission to a reviewing user.