Rubrik, the cybersecurity software startup that Microsoft invested in at a $4 billion valuation in 2021, plans to go public in New York as early as April, as it handles a U.S. fraud investigation into one of its former employees, according to people familiar with the matter.

The probe, which has not been previously reported, is being carried out by the U.S. Department of Justice and is focused on a person who worked for Rubrik’s sales division, two of the sources said.

The DOJ is looking into whether the former employee diverted funds paid by the U.S. government for 110 contracts with Rubrik into an operating entity he had created, one of the sources said. The source said the contracts were worth a total of $46 million, but did not disclose the amount allegedly diverted by the employee.

Rubrik is cooperating with the investigation and hopes it will be wrapped up by the end of March so it can launch its initial public offering (IPO), the sources said. If this pans out, Rubrik, which has already registered the IPO confidentially with the U.S. Securities and Exchange Commission, will be a publicly traded company as early as April, the sources added.

The sources requested anonymity because the matter is confidential. Rubrik declined to comment, while the Department of Justice and Microsoft did not immediately respond to requests for comment.

Reuters reported last year that Goldman Sachs, Barclays and Citigroup would lead Rubrik’s IPO as underwriters.

Founded in 2014 by venture capitalist Bipul Sinha, Rubrik makes cloud-based ransomware protection and data backup software. The company serves more than 5,000 business customers, including Nvidia and Home Depot.

Rubrik generates annual recurring revenue of over $600 million, and its overall revenue is growing in high single-percentage digits, according to the sources.

The company has so far raised more than $1 billion in equity and debt from investors including Greylock Partners and Lightspeed Venture Partners, according to PitchBook.

The U.S. IPO market has yet to recover from two years of subdued activity. Arc’teryx maker Amer Sports priced its $1.375 billion offering below its indicated price range this week, after BrightSpring Health Services also discounted its IPO last week.