He is one of 36 suspects from across the globe indicted over their roles within the group, which is said to have committed "large-scale acquisition, sale and dissemination" of stolen identities, debit and credit cards and other sensitive information.
The US Justice Department named the Australian man as 27-year-old Edgar Rojas aka Edgar Andres Viloria Rojas, aka Guapo, aka Guapo1988, aka Onlyshop.
Five members of the group, known as the Infraud Organization, were arrested in the U.S.
Cronan said it was believed the group had meant to cause losses totaling more than $2.2 billion during their seven years of operation.
The Americans involved with Infraud have already appeared in court, and they could face more than 30 years in prison if they're found guilty.
Prosecutors in the case, which was unsealed in Nevada, allege that the group was created in October 2010 by Svyatoslav Bondarenko, a Ukranian who sought to create "the premier destination" for purchasing retail items on the internet with counterfeit or stolen credit card information.
The US Department of Justice described the operation as "one of the largest cyber fraud enterprise prosecutions" it had ever undertaken.
Lower down were super moderators and moderators who served as subject-matter experts over specific topics or regions.
Those arrested stand accused of multiple crimes including identity theft, bank fraud, wire fraud and money laundering. He is alleged to operate a trusted "escrow" or currency exchanging service to ensure transactions between Infraud members, according to the Department of Justice.
The takedown of Infraud - dubbed Operation Shadow Web - was an global effort and the Australian Federal Police was among the law enforcement agencies thanked by the Department of Justice for their role.
VIP Members and Members used the Infraud forum to gather information and to facilitate their criminal activities.
The site directed potential buyers to the automated vending sites of other members who possessed stolen financial, banking, or personal identification data, malware, or other illicit goods.
"After Bondarenko went missing in 2015, [Sergey] Medvedev took his place as owner and administrator of the Infraud Organization", the indictment read.