Hawkfish will be the "primary digital agency and technology services provider for the campaign," Julie Wood, a Bloomberg campaign spokeswoman, told CNBC. She added that the firm "is now providing digital ad services, including content creation, ad placement and analytics" for their campaign. It will also help Democratic races across the country in future election cycles, she said.

Presidential candidate Mike Bloomberg is pouring tens of millions of dollars from his vast personal fortune into his campaign . A piece of it is going to an unknown digital business called Hawkfish — which Bloomberg himself founded during the spring.

The company's existence has not been previously reported. Bloomberg's campaign disclosed details about the company after CNBC pressed the campaign about its recent hiring spree.

Bloomberg, a billionaire former three-term mayor of New York, started building the company early in 2019, before he decided to seek the Democratic presidential nomination, the campaign aide said. While the campaign declined to say how much Bloomberg has invested in the company, Bloomberg has said he will spend over $100 million on anti-Trump digital ads. His campaign has already spent at least $13 million on Facebook and Google spots.

Bloomberg, who was dedicated to denying President Donald Trump a second term before he entered the Democratic race, built Hawkfish with the intention of overpowering the formidable data operation assembled by the Republican National Committee and Trump's cash-flush campaign.

Hawkfish appears to have been assembled in secret. It has no public website. A search of elections databases turned up no financial records connected to work for other Democratic causes.

No other candidate in the 2020 race is known to have created a vendor designed to aide their bid.

While it is unusual for a presidential candidate to turn to a company he founded for assistance, ethics experts say Bloomberg's move does not break Federal Election Commission laws.

"I would say nothing shows a red flag as far as a violation," Paul S. Ryan, vice president of policy and litigation at Common Cause, told CNBC. "If he sincerely had not made up his mind to run when he made this company to help Democrats, it's fine. Going forward, the campaign would have to pay fair market value to the company in goods that he's receiving."

It's not entirely clear where the company is based.

Using research company Accurint, CNBC reporters went to a New York address that was associated with Hawkfish. At the address, 909 Third Avenue, an attendant at the front desk said no business named Hawkfish existed there. The Bloomberg campaign spokeswoman said the address, which is about a five-minute walk from Bloomberg's namesake company, was only used for receiving paperwork. The address is the same as Mike Bloomberg's longtime accountant, Geller & Company.

Bloomberg has prioritized data analytics in his business and public life. Bloomberg LP, a financial services and data company, rose to success on the strength of its "terminals," or data hubs. He relied on a data-driven approach through his 12 years as mayor of the nation's largest city.

He is known to use the phrase, "In God we trust. Everyone else bring data," and is selling merchandise with the slogan on his campaign website.

A year after he poured over $110 million to help elect Democrats in the 2018 congressional midterm elections, Bloomberg and his aides started to reach out to business leaders in the tech world to start exploring the idea of making a company that could help Democrats and combat Trump. Bloomberg himself met with the likes of longtime Silicon Valley investor Ron Conway and New York-based venture capitalist Fred Wilson.

Conway told CNBC in an email that he spoke with Bloomberg about the necessity of creating a digital counterweight to Trump and the Republican Party.

"It's clear to me and other tech leaders that Trump and the GOP are better at creating and sharing engaging online content than anyone on the Democratic side," Conway said in explaining his conversation with Bloomberg. "If we want to win in 2020 and beyond, we need to master the digital medium in our own effective way, including efficiently registering voters and sharing compelling content with the right audiences. The battle is being waged online and so far Democrats have been out-matched — if Mike can help us catch up, that will make a big difference."

Wilson did not return a request for comment.

Soon after Hawkfish incorporated in the spring, it started working on behalf of Democratic groups involved in races in Virginia and Kentucky. The Bloomberg campaign did not say which races Hawkfish worked on, and Democratic groups in those states did not respond to requests for comment.

In November, Democrats won control of the Virginia statehouse for the first time in more than two decades. Bloomberg's gun control group, Everytown for Gun Safety, outspent the National Rifle Association in Virginia and has received credit for helping Democrats flip the legislature.

In Kentucky, Democrat Andy Beshear narrowly defeated Republican Gov. Matt Bevin. The state had favored Trump by about 30 percentage points in 2016.

Hawkfish's leadership ranks include longtime Facebook Chief Marketing Officer Gary Briggs, who recently posted on his social media page that he is now a digital director at "Mike Bloomberg 2020," and Jeff Glueck, former CEO of location-tracking firm Foursquare.

Glueck said on Twitter that he was moving over to Hawkfish full time after working as an advisor for a few months. He noted that the firm had worked for state-level Democratic campaigns but said the company's first "major" customer was Bloomberg's campaign for president. He announced on Twitter earlier in December that he was leaving Foursquare.