Computer security firm Norton buys Avast for over $8 bn

US cyber security giant NortonLifeLock has agreed to buy Czech rival Avast for more than $8 billion (6.7 billion euros) to create a leading cyber consumer business, the pair announced Wednesday.

"This transaction is a huge step forward for consumer cyber safety and will ultimately enable us to achieve our vision to protect and empower people to live their digital lives safely," Norton chief executive Vincent Pilette said in a joint statement.