What happened

Shares of Okta (OKTA 1.53%) were falling again as new details emerged about a data breach of the cloud-based identity-as-a-service software company.

As of 12:50 p.m. ET, the stock was down 8.1%. It had fallen nearly as much yesterday before recovering most of those losses in a broad market rally.

A person typing on a keyboard with an image of a lock overlaid.

Image source: Getty Images.

So what

Yesterday, Lapsus$, a hacker group, published screenshots from a computer used by one of Okta's third-party engineers. In a follow-up post after hours last night, Chief Security Officer David Bradbury explained that after an investigation into the hacker's claims, it found that at most 366 of its customers, or approximately 2.5% of its customers, were potentially impacted by the hack. The company said it had already contacted those customers directly by last night.

Bradbury also said Okta's service is fully operational. Separately, Microsoft reported that Lapsus$ had stolen source code from it after getting limited access. 

Now what

The fallout from the breach is unclear at this point, but Okta is already facing criticism for not revealing the potential hack earlier as the event occurred in January. The company did not address it publicly until Lapsus$ posted screenshots yesterday as Okta said it was awaiting investigation of the incident.

In a separate blog post, Bradbury said he was "greatly disappointed" by how long the investigation took, and said that the hacker did not successfully log in to the engineer's computer, but was able to access it remotely. 

Since Okta's business is providing companies with secure identity management including log-ins and access, the incident could damage its reputation. A full report should come later, but it's not surprising that the stock is cooling off again today.