A UK Foreign Office spokesperson said that they are in contact with authorities in Las Vegas and are providing help to Hutchins' family.
The Department of Justice alleges in its indictment that Hutchins' co-conspirators demonstrated how Kronos worked on a publicly available website in July 2014 and offered to sell Kronos for $3,000 in August 2014.
Hutchins' friend, Andrew Mabbit, a United Kingdom security researcher also in Las Vegas for the conferences, confirmed his detainment, noting Hutchins had no present legal representation and that an effort was underway to provide it. A spokesperson for U.S. Marshals told Motherboard it was an Federal Bureau of Investigation arrest, but could not provide further details.
The US government is accusing Hutchins of creating and distributing Kronos, a Russian banking trojan that first popped up in 2014 and stole from online banks.
US law officials told CNN the charges are related to the creation and distribution of "the Kronos banking Trojan". That so-called "Kill Switch" allowed Hutchins to effectively disable the malware just a day after it made headlines.
Andrew Mabbitt, founder of cyber firm Fidus Information Security, said on Twitter that he was working to obtain a lawyer for Hutchins because he lacked legal representation.
The UK's National Crime Agency confirmed a British citizen had been arrested.
"I've spoken to the US Marshals again and they say they have no record of Marcus being in the system".
A defender of Hutchins said, "law enforcement may have misinterpreted actions Hutchins took to find a way to protect against Kronos".