A server registered to the Trump Organization was found to have been in contact with a Russian bank, reported Slate. According to the report, Trump was “secretly communicating” with AlfaBank in Russia. Trump’s denied any ties to Russia during the election—though suspicions about Russian ties already caused the resignation of Trump’s campaign chairman Paul Manafort, who had worked for Russian President Vladimir Putin. This past summer, Trump also encouraged Russians to hack Hillary Clinton.

Slate spoke to one scientist, who was referred to as Tea Leaves for purposes of anonymity, and two of his close collaborators. After seeing Russian hackers attack the Democratic National Committee, a group scientists reportedly began looking into Russian malware to make sure Trump’s campaign wasn’t attacked. “We wanted to help defend both campaigns, because we wanted to preserve the integrity of the election,” said one academic.

Tea Leaves said he found malware coming from Russia and saw Trump’s name in the destination domain, leading him to monitor Trump server’s DNS activity. “I have an outlier here that connects to Russia in a strange way,” Tea Leaves recalled writing in his notes.

“When the researchers pinged the server, they received error messages. They concluded that the server was set to accept only incoming communication from a very small handful of IP addresses,” Slate wrote. The server would later reportedly be shut down.

It's time for Trump to answer serious questions about his ties to Russia. https://t.co/D8oSmyVAR4 pic.twitter.com/07dRyEmPjX — Hillary Clinton (@HillaryClinton) October 31, 2016

Top DNS expert Paul Vixie was shown the information gathered by the scientists. Vixie concluded: “The parties were communicating in a secretive fashion. The operative word is secretive. This is more akin to what criminal syndicates do if they are putting together a project.”

The Trump campaign denied the report in a statement to Complex:

“The only covert server is the one Hillary Clinton recklessly established in her basement while serving as Secretary of State, compromising our national security. “A file of incomplete logs recently provided for review by The Trump Organization regarding speculative “email” communication with the IP address of a financial institution in Russia named AlfaBank failed to determine any instance of two-way email communication. The partial logs confirmed an IP address belonging to AlfaBank sent common DNS internet traffic “lookups”, not email traffic. The domain mail1.trump-email.com was configured in 2010 for promotional consumer email marketing campaigns by Trump Hotels and operated by a 3rd party vendor, Cendyn. “A thorough network analysis conducted by Cendyn at the request of The Trump Organization determined an existing banking customer of Cendyn, completely unrelated to Trump, recently used Cendyn’s “Metron” Meeting Management Application to send communication to AlfaBank.com. Cendyn uses internal and external SMTP servers for various applications that are not dedicated to specific clients, nor affiliated or paid for by any Trump entity. "To be clear, The Trump Organization is not sending or receiving any communications from this email server. The Trump Organization has no communication or relationship with this entity or any Russian entity."

Hillary for America Senior Policy Advisor Jake Sullivan also released a statement in response to the report:

Computer scientists have apparently uncovered a covert server linking the Trump Organization to a Russian-based bank. pic.twitter.com/8f8n9xMzUU — Hillary Clinton (@HillaryClinton) November 1, 2016

Mother Jones reported a former spy who spent almost 20 years working on Russian intelligence matters said he had to research Trump’s dealings with Russia, sending a report to FBI. In his report the officer wrote: "Russian regime has been cultivating, supporting and assisting TRUMP for at least 5 years. Aim, endorsed by PUTIN, has been to encourage splits and divisions in western alliance." That assistance allegedly included receiving information from the Kremlin on Democratic and other political rivals.