The new website, called Garlik, appointed Fallon after a round of meetings with several other unnamed London agencies.
The business includes a brief to mastermind the strategic positioning of Garlik's launch, as well as straightforward creative duties.
offers consumers a range of products and services to protect their personal data. It claims to help users protect their personal information from identity theft and online fraud.
Garlik also counts Tom Ilube, former chief information officer of Egg, among its founders. It has been set up with funding from private equity group 3i and the venture capital fund Doughty Hanson & Co.
Robert Senior, founding partner of Fallon, said: "The brief is straightforward and scary; taking the web back to Tim's original vision of empowerment."
The win is the latest in a series of new-business successes for Fallon following on from winning Asda's £44m creative account and a brief from confectionery giant Cadbury Trebor Bassett for an Australian sweet brand.