Oct 20 (Reuters) - Okta on Friday disclosed a breach of its customer support system that allowed some hackers to view files uploaded by certain clients, pushing the software company's shares down about 12%.

"Okta security has identified adversarial activity that leveraged access to a stolen credential to access Okta's support case management system," Chief Security Officer David Bradbury said in a blog.

He did not specify the customers affected or the nature of the data that was compromised.

The company said its support case management system was different from production Okta service, which was fully operational and was not impacted.

The San Francisco-based company provides identity services, such as single sign-on and multi-factor authentication that are used for logging in to online applications and websites, to a customers including Microsoft-backed OpenAI.

Okta shares ended down 11.6% at $75.57.

(Reporting by Yuvraj Malik in Bengaluru; Editing by Sriraj Kalluvila)