The statement added: "The investigations confirm that none of Proactis' customer systems were compromised and only a very small amount of low level internal and non-commercially sensitive data, limited to a standalone, services-based business unit in the US was accessed by the perpetrators.
"The effectiveness of the network segregation we have in place played a key part in protecting us during the incident.
"The company confirms there will be no material financial impact on Proactis as a result of the incident."
"The company will continue to work with the relevant regulators and law enforcement agency, including the Information Commissioner's Office, to ensure that any follow up action required takes place."
Tim Sykes, Chief Executive Officer of Proactis, said: "Our response to this cyber incident has been highly professional, putting our customers and employees first at all times.
"Our robust business continuity plans worked well. We also remain grateful that our network segmentation and wider IT infrastructure monitoring limited the impact of this incident on our wider business."
Proactis creates, sells and maintains software and services which enable organisations to streamline, control and monitor all indirect expenditure.