A computer-implemented method for controlling access to a user-facing session of an application running on an endpoint computing device, the method comprising: engaging, by a security server, in an agentless management session with the application running on the endpoint computing device, wherein: the application is configured for use by a user, the user-facing session of the application is a session during which the user interacts with the application, and the agentless management session is a session implemented through code received by the application from the security server; controlling, by the security server and through the agentless management session, the user-facing session of the application running on the endpoint computing device, wherein the controlling comprises instructing the endpoint computing device to transmit activity data and proximity data associated with the endpoint computing device and one or more personal computing devices (102, 103, 104) associated with the user to the security server; receiving, by the security server, the activity data and proximity data from the endpoint computing device; detecting, by at the security server, based on the activity data and proximity data, an indication of at least one of: anomalous activity of at least one of: the user, the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user, or a loss of a proximity between at least one of: the one or more personal computing devices (102, 103, 104) associated with the user and the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user and the user; and implementing a control action in the agentless management session, based on the detected indication, wherein the control action in the agentless management session controls an attribute of the user-facing session of the application running on the endpoint computing device. the application is configured for use by a user, the user-facing session of the application is a session during which the user interacts with the application, and the agentless management session is a session implemented through code received by the application from the security server; controlling, by the security server and through the agentless management session, the user-facing session of the application running on the endpoint computing device, wherein the controlling comprises instructing the endpoint computing device to transmit activity data and proximity data associated with the endpoint computing device and one or more personal computing devices (102, 103, 104) associated with the user to the security server; receiving, by the security server, the activity data and proximity data from the endpoint computing device; detecting, by at the security server, based on the activity data and proximity data, an indication of at least one of: anomalous activity of at least one of: the user, the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user, or a loss of a proximity between at least one of: the one or more personal computing devices (102, 103, 104) associated with the user and the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user and the user; and anomalous activity of at least one of: the user, the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user, or a loss of a proximity between at least one of: the one or more personal computing devices (102, 103, 104) associated with the user and the endpoint computing device, or the one or more personal computing devices (102, 103, 104) associated with the user and the user; and implementing a control action in the agentless management session, based on the detected indication, wherein the control action in the agentless management session controls an attribute of the user-facing session of the application running on the endpoint computing device.