Cloud-based Intrusion Prevention Systems (IPS) include receiving traffic associated with a user of a plurality of users, wherein each user is associated with a customer of a plurality of customers for a cloud-based security system, and wherein the traffic is between the user and the Internet; analyzing the traffic based on a set of signatures including stream-based signatures and security patterns; blocking the traffic responsive to a match of a signature of the set of signatures; and performing one or more of providing an alert based on the blocking and updating a log based on the blocking.