US payroll-handling firm Automatic Data Processing (ADP) said Wednesday that hackers broke into one of its benefits administration business systems.
ADP believed the "system intrusion" at recently acquired Workscape was limited to one client, whose name was not disclosed.
"ADP immediately notified the client... and continues to take all appropriate measures to investigate and to help mitigate any issues," the New Jersey-based company said in a release.
The hack was detected by routine security monitoring and did not involve payroll information, according to ADP, which said it was working with law enforcement to investigate the incident.
The hack was the latest in a growing list of cyber attacks with targets ranging from videogame companies to the US Senate and a military weapons maker.
Explore further: Twitter expands privacy on direct messages