After an anemic February — when American Crossroads brought in only $260,000 — the super PAC scored big in March, raising over $5.2 million, including big checks from familiar donors like hedge fund mogul Paul Singer, leveraged buyout artist John W. Childs and former Univision chairman Jerry Perenchio, who chipped in $2 million.

But while big donors came up big in March, a pair of obscure companies made up more than half of American Crossroads’ more modest take in February — ones that do not disclose their ownership in corporate filings.

American Crossroads’ February fundraising suggests that the practice of hiding the identity of donors to super PACs behind limited liability companies will continue in 2014. Called LLCs, these companies can be owned and operated by any number of individuals, corporations or interests, and are established under state laws.

Not only can they donate money to super PACs while obscuring the identity or identities of the donors behind them, they can also spend directly to influence elections. A recently formed conservative group that churns out ads attacking Democrats, America Rising, organized as an LLC rather than a political committee, and CQ Roll Call reported that conservatives‚ increasingly frustrated with the Internal Revenue Service handling of the tea party nonprofit applications, may turn to LLCs as an alternative to dark money groups like Crossroads GPS that do not disclose their donors.

The latest FEC filing from American Crossroads lists two donors, LMD Properties LLC and Boston Holding Company LLC, which gave $50,000 and $100,000 contributions, respectively. Neither company has a website and neither is listed at the addresses they provided American Crossroads.

LMD Properties is listed in the PAC filing as being based in Greensboro, N.C. Its property tax filings with the Guildford County Tax Department in North Carolina indicate the company’s current mailing address is shared by New Breed Corp., which, according to its website, specializes in “solutions and infrastructure for supply chain transformation.”

A North Carolina Secretary of State filing lists Louis DeJoy as the company’s manager. DeJoy is also chairman and CEO of New Breed. Since 2009, he’s contributed $175,300 to Republican committees, and his wife, Aldona Zofia Wos, is a Republican fundraiser and served as ambassador to Estonia for President George W. Bush.

Though LMD Properties formed in 1998, a search of contributions from Influence Explorer’s bulk data shows this is the first year the company has donated to a federal committee.

The second company in American Crossroads’ filings, Boston Holding Company, LLC, shares an address with Boston Asset Management Inc. in Clearwater, Fla. That firm manages wealth for individuals and institutions; it also advertises its services to athletes. The Florida Department of State’s Division of Corporations website indicates the company was registered by Jonathan Golden, but lists Leo J. Govoni as an “authorized person.”

In December 2013, Govoni entered Florida’s 2014 general election for state representative in District 69. He bowed out of the race on March 3rd of this year, but before doing so, he raised more than $73,000 according to the Florida Department of State’s Division of Elections.

Both Golden and Govoni have ties to the Boston Finance Group, a private equity company that current U.S. Rep. David Jolly, R-Fla., joined in 2012 as vice president. Sunlight’s Influence Explorer shows Govoni and Golden both donated to Jolly’s campaign. The Tampa Bay Times found Govoni and Jolly also have multiple business, however, Govoni claims it did not influence his run for office.

As of this posting, neither Boston Asset Management Inc. nor New Breed Corp. have returned calls requesting more information about their affiliation with the LLCs.

In 2011, NBC News reported on a $1 million contribution to Restore Our Future super PAC, which backed Mitt Romney in the GOP primaries and the general election, from W Spann LLC that dissolved within a month after making the donation. Ed Conard, who had previously been employed at Bain Capital, the asset management firm Mitt Romney co-founded, eventually identified himself as the donor behind the LLC.

Other limited liability corporations also tested the waters. In 2012, Sunlight reported on three companies — all linked to one man, Robert T. Brockman — that collectively donated $1 million to Restore Our Future. When the New York Times investigated another such donor, Glenbrook LLC, which contributed $250,000 to Restore our Future, it found a network of difficult-to-trace P.O. box addresses and could not identify the individuals behind it.