VP Communications had held the account for the past two years.
Cybertrust, headquartered in Virginia, with 30 offices worldwide, claims to be the world's largest independent security specialist, working with more than 4,000 organisations and four of the top five global banks.
The agency switch follows a review by EMEA head of PR Sarah Pocock, who joined in August.
ITPR will run a B2B campaign targeting the financial, manufacturing and retail sectors to boost awareness of the company.
‘We want to move away from product-based PR and concentrate on building the brand and promoting the services,' said ITPR senior partner Bob Dearsley.