Bite will aim to build brand recognition of Webroot, with activity focusing on strategic media, analyst relations and customer advocacy, as well as positioning the business as a thought leader in the internet security sector.
The agency's work will focus on five key markets: the UK, US, Japan, Germany and Australia.
Rocket had previously handled comms work for Webroot in the UK and rest of Europe.
Webroot executive vice-president product and strategy Michael Malloy said: ‘To achieve market dominance requires the perfect combination of drive and business sense, and the best public relations and marketing comms partner possible.
'Bite was chosen because it mirrors our passion and shares the common goal of taking the leadership position in our respective markets.’
Bite CEO Andy Cunningham said: 'Webroot has all the ingredients to be a great success story. Complementing the company's innovative offerings and strong leadership team with Bite's calculated global and local comms strategy will help Webroot clearly articulate its point of differentiation to businesses, consumers and partners.'