Ultimate Kronos Group may need to keep its systems offline for weeks following a ransomware attack, which has affected only customers who use the Kronos Private Cloud. The hack included scheduling products specifically designed for health care systems, financial institutions and public safety workers.

“We took immediate action to investigate and mitigate the issue, have alerted our affected customers and informed the authorities, and are working with leading cybersecurity experts,” a company spokesperson told NPR. “We recognize the seriousness of the issue and have mobilized all available resources to support our customers and are working diligently to restore the affected services.”