A Tuesday arraignment has been postponed for a British cybersecurity researcher who was arrested last week in Las Vegas on charges that, years before he won acclaim for helping to stop a worldwide ransomware attack, he created and distributed a malware program to pilfer banking passwords from unsuspecting computer users.

Marcus Hutchins, 23, of Ilfracombe, England, has a new arraignment date of Aug. 14 in federal court in Milwaukee, according to Elizabeth Makowski, a spokeswoman for the U.S. Attorney's Office in the Eastern District of Wisconsin.

Hutchins was being held Monday in federal custody in a jail outside Las Vegas, where he was arrested last week at McCarran International Airport following the Def Con convention for computer security professionals.

Electronic Frontier Foundation general counsel Kurt Opsahl said he was awaiting word that bail had been posted and that Hutchins has been released from federal custody. The foundation, a digital civil-liberties nonprofit, was helping Hutchins obtain legal counsel.

Hutchins' attorney in Las Vegas, Adrian Lobo, didn't immediately respond to telephone and email messages from The Associated Press.

Hutchins is scheduled to appear Tuesday morning in federal court in Milwaukee on six charges, including conspiracy to commit computer fraud in 2014 and 2015. He is accused of creating and distributing malicious software called Kronos designed to steal banking passwords.

Hutchins was credited with helping in May to curb the spread of WannaCry ransomware during an attack that crippled thousands of computers worldwide.

U.S. Magistrate Judge Nancy Koppe in Las Vegas said when she set bail at $30,000 that he could be released Monday. The judge decided Hutchins was not a danger to the community and wasn't a risk not to appear for future court proceedings.