Automatic Data Processing which is one of the world's biggest payroll processors has admitted that it has been hacked. ADP is investigating a data breach affecting one of its corporate clients and said it is "taking measures to address the impact" of the breach.

It looks like the hack happened at a benefits administration unit ADP recently bought, and was limited to a single client. A server which had a "non-payroll" product that it is no longer sold was taken down.

ADP has about 550,000 clients and is best known for managing their payrolls. But it also provides other services, including administering benefits programs and providing computer services. The outfit said that it is working with coppers and other officials to identify the cause of the breach and to catch the hackers.

It seems that the hackers are having a field day with financial companies at the moment. Many observers have commented that the attacks seem to prove that whatever the financial services companies are doing on security.