Hewlett Packard Enterprise (HPE) has acquired security startup Niara, a deal that brings former Aruba executives back to the roost.

WiFi vendor Aruba was acquired by HPE in 2015. By that point, Niara was already born; its founders had left Aruba and raised a round of funding. That group included CEO Sriram Ramachandran and Vice President of Engineering Prasad Palkar.

They'd previously worked on the security aspects of ArubaOS, according to an HPE blog posting today by Keerti Melkote, who is general manager of HPE Aruba and was an Aruba founder as well.

Niara specializes in behavior analysis. It uses machine learning and big data to establish a baseline for normal behavior, then looks for anomalies that could indicate intrusions.

That's in line with a current trend in security: looking for ways to minimize damage after a network has been breached. Other companies applying machine learning and/or big data techniques to this problem include startups Deepfield (being acquired by Nokia) and Vectra, as well as non-startup AT&T, with its Threat Intellect platform.

Terms of the deal were not disclosed. Niara had raised $29.4 million in two rounds, the latest one being a $20 million Series B in April 2015.

HPE's other recent acquisitions include hyperconverged infrastructure vendor SimpliVity, for $650 million, and analytics firm Cloud Cruiser, for an undisclosed sum.