One of the world’s largest providers of human resources technology, Workday, has confirmed a data breach that exposed personal information from a third-party database linked to its systems.

In a statement published late Friday, the company said hackers accessed a customer relationship database containing contact details such as names, email addresses, and phone numbers. Workday did not say how many people were affected, but warned that the stolen information could be used in social engineering attacks, where victims are tricked into revealing sensitive data.

The company stressed there was “no indication of access to customer tenants or the data within them,” referring to the core systems used by Workday’s more than 11,000 corporate clients to manage employee records for an estimated 70 million users worldwide.

Workday did not identify the compromised third-party platform. However, the incident follows a string of recent cyberattacks against Salesforce-hosted databases used by major corporations. In recent weeks, Google, Cisco, Qantas, and Pandora have all confirmed data thefts linked to Salesforce.

Google has blamed the breaches on *ShinyHunters*, a notorious hacking group known for using phone-based phishing to trick employees into giving up access credentials. The group is believed to be preparing a data-leak site to pressure victims into paying to prevent stolen data from being published.

Workday declined to say whether it can determine whose information was stolen, or how many individuals are affected. Its blog post announcing the breach, first spotted by Bleeping Computer on August 6, was also found to contain a “noindex” tag — code that prevents search engines from listing the page.

The reason for concealing the disclosure remains unclear, raising questions about Workday’s transparency as it deals with the fallout of the attack.