During inspection of your Threat Prevention logs you find four different computers having one event...

 The host having a Critical event found by Anti-Bot should be remediated first, as it indicates that the host is infected by a botnet malware that is communicating with a Command and Control server. This poses a serious threat to the network security and data integrity. The other events may indicate potential malware infection or attack attempts, but not necessarily successful ones. References: Threat Prevention Administration Guide