Monero is difficult to track, making it a favored commodity among scammers and cybercriminals.
Further, the criminals posted what they claimed was their encryption key, purported to verify that whatever information they posted came from them. The key was associated with an email address at an internet site that doesn't exist.
The Trump campaign website was restored a short time later.
In a statement via CBS News, Trump campaign spokesperson Tim Murtaugh said that no data had been stolen.
"Earlier this evening, the Trump campaign website was defaced and we are working with law enforcement authorities to investigate the source of the attack. There was no exposure to sensitive data because none of it is actually stored on the site. The website has been restored," Murtaugh said.
How the hackers gained access to the site is unclear. However, Perloth noted that one possibility is that they tricked the site's administrator into giving up the password, such as through email "phishing" or a similar scam.
The hack came amid concerns about both the electronic security of the voting and vote-counting process, as well as possible foreign interference in the U.S. election.
Last week, John Ratcliffe, the director of national intelligence, claimed that Iran and Russia had both carried out limited attacks on the voting process in the past few weeks. In one case, hackers were able to gain limited access to some voter registration databases. In another, threatening emails, purportedly from the far-right group Proud Boys, were sent to voters in Florida. Those emails relied on publicly available information and were written in broken English.