Terms of the deal were not disclosed, but Astaro booked $56 million in billings last year, which makes it the fourth largest dedicated unified threat management (UTM) provider in the world.
Astaro was founded in 2000 and is headquartered in Karlsruhe, Germany and Wilmington, USA. The company currently boasts more than 220 employees in nine countries, including a significant presence in the EMEA region.
The company raised a total of $12.9 million from Wellington Partners, Insight Venture Partners and OpenView Venture Partners.
The network security appliance maker says it has completed over 56,000 installations in over 60 countries, protecting business, school and government networks against a variety of IT security threats such as data theft, viruses, spyware and spam.
Astaro also boasts a network of over 2,500 channel partners.
With the acquisition of Astaro, Sophos aims to deliver coordinated protection and policy between endpoint and network to its clients, along with integrated management and reporting.