Sophos on Friday announced plans to acquire private network security firm Astaro for an undisclosed sum. Astaro, founded in 2000 and headquartered in Karlsruhe, Germany and Wilmington, Mass., is the world's fourth largest provider of unified threat management (UTM) solutions, Sophos said in a news release. Such technology offers multiple security functions, including network, web, mail and web application protection, through a single platform. Astaro's portfolio will bolster Sophos' existing endpoint, mobile, email, web and data protection capabilities, the company said.