The firm has bought Websense Enterprise Client Policy Manager (CPM) for its South-East regional offices.
Websense said the tool prevents the use of unauthorised applications, such as hacking, spyware, and access to peer-to-peer networks.
"All IT managers should be aware of the threats that employee internet use can bring," siad Antony Wiltshire, IT manager for the south-east region of Northcliffe. "The downloading of seemingly innocent applications can contain a host of spyware and malicious mobile code, as can peer-to-peer file-sharing applications."
Northcliffe deployed the tool to improve employee productivity and prevent network abuse. The tool be used in two ways - white or black list applications. Northcliffe decided to limit employees' use of programmes to those on the white list.
The Group said it intends to roll-out the software across its national offices by September 2004.