(Reuters) - Cisco Systems Inc <CSCO.O> said on Tuesday it would buy OpenDNS, a privately held cloud-based security company, for $635 million in cash and equity awards to beef up its security business.
Cisco has been buying a number of security companies to boost the business in the face of fast-growing, sophisticated cyber attacks.
OpenDNS provides network security service that block attacks, as well as malware, botnets and phishing threats. Cisco was part of a group that invested $35 million in OpenDNS in May last year.
The acquisition of San Francisco, California-based OpenDNS is expected to close in the first quarter of fiscal year 2016, Cisco said in a statement.
Cisco bought security advisory firm Neohapsis for an undisclosed sum this year and malware analysis company ThreatGRID in 2014.
The global cybersecurity market is estimated to grow to $170.21 billion by 2020 from $106.32 billion in 2015, according to market research firm MarketsandMarket.
Cisco's shares were up 0.76 percent at $27.75 in premarket trading.
(Reporting by Abhirup Roy and Anya George Tharakan in Bengaluru; Editing by Savio D'Souza)