A system and a method are disclosed for describing a mechanism for tracking malicious activity detected on a network. For example, based on network data collected from a server, the disclosed system may detect malicious activity originating from a client device directed to the server. To detect the malicious activity, network data may be captured by the server and analyzed. When malicious activity is detected, the system may track the malicious activity, using the network data, to an earliest connection date of a client device from where the malicious activity potentially originated. The earliest connection date may indicate a potential start date of the malicious activity.