System and Method for Detecting Security Intrusions and Soft Faults Using Performance Signatures

A method for detecting security intrusions and soft faults in a software system includes receiving a multi-dimensional performance signature built from operating system metrics sampled by a software system monitoring infrastructure, associating a plurality of buckets with each component of the performance signature, comparing a component of the sampled performance signature to an expected value for the performance signature component, where a bucket for the performance signature component is incremented if the sampled performance signature component exceeds the corresponding expected value, and the bucket for the performance signature component is decremented if the sampled performance signature component is less than the corresponding expected value, executing a security alert notification when the bucket for the performance signature component exceeds a first threshold, and executing a soft-fault notification when the bucket for the performance signature component exceeds a second threshold, where the first threshold is less than the second threshold.