Rana Reeves, founder of John Doe and account lead, said social media would be at the heart of the work, with content and campaigns looking to "create spikes in conversation" about the brand.
The agency beat incumbent Tea & Cake PR and two others in a pitch for the brief, which is thought to be worth a six-figure sum.
Adam Boita, marketing controller at Pernod Ricard UK, said: "We are highly ambitious for our Malibu brand, where our vision is to take the spirit of summer to the 18- to 24-year-old generation. To achieve this we are focusing increasingly on working with influencers, celebrities and media partners to generate content that can be leveraged through digital, social and traditional print."
On the work with incumbent Tea & Cake, he added: "We have been extremely proud of the work that Tea & Cake has produced for Malibu over the past five years including the award-winning Malibutique. We will maintain a close relationship working with it on bespoke projects within the Pernod Ricard UK portfolio of brands."