An Opelousas man is one of 70 around the world accused of taking part in an online forum that authorities said enabled its exclusive group of users to buy, sell, trade and share information and tools used to intrude on electronic devices.

Federal authorities on Tuesday arrested Rory Stephen Guidry, 28, on a count of computer fraud in the undercover investigation dubbed “Operation Shrouded Horizon.”

“Clever computer criminals will not be able to hide or maintain their anonymity even as they cross national boundaries,” U.S. Attorney Stephanie Finley, with the Western District of Louisiana, said Thursday in a statement. “Through the coordinated response and international cooperation of our law enforcement partners, individuals such as these who are involved in computer hacking forums will see their organizations dismantled, and they will be prosecuted to the fullest extent of the law.”

In an affidavit for Guidry’s arrest, FBI Special Agent Randy Jordan said the accused hacker operated and sold access to a botnet, in which Web-connected, security-breached computers are controlled by a malicious third party.

Hundreds of thousands of computers can act in unison under the hacker’s control, whether to send spam emails, be scraped for sensitive data, distribute other malware or diminish the systems’ functionality by overloading them with traffic.

The malware distributed through these computer webs also blocks access to more than 100 popular antivirus and security programs, “so the user cannot download the software to fight the malware,” Jordan wrote in the affidavit.

Users of the infected computers also could fall victim to ransomware, a type of malware that locks users out of their systems until they pay a ransom online.

“Guidry is an intelligent, malicious hacker who implements operational security, using techniques which attempt to hide his criminal cyber activities from law enforcement,” Jordan wrote.

The FBI infiltrated the forum and investigated Guidry with help from “a very experienced computer hacker” — whose name is redacted in the affidavit — who had been a member of the forum for about four years. It’s unclear whether that person is a civilian informant or FBI agent.

“Through this operation, we have dismantled a cyber hornets’ nest of criminal hackers which was believed by many, including the hackers themselves, to be impenetrable,” U.S. Attorney David J. Hickton, of the Western District of Pennsylvania, said in a U.S. Department of Justice news release announcing the bust.

Since 2007, Darkode served as an online, password-protected forum where its users were vetted through an invite-only process, and it provided a marketplace for those users to buy, sell and trade things like hacking tools, spamming services and stolen credit card numbers and financial data.

A visit to the forum — darkode.me — on Thursday revealed an inoperable site marked with a seizure notice plastered with the badges of the 20 investigating agencies involved in its takedown.

“This is a milestone in our efforts to shut down criminals’ ability to buy, sell and trade malware, botnets and personally identifiable information used to steal from U.S. citizens and individuals around the world,” FBI Deputy Director Mark F. Giuliano said in the release.

Agents at the FBI’s Pennsylvania field office led the investigation.

Along with a handful from the U.S., those implicated in the case come from Australia, Bosnia and Herzegovina, Brazil, Canada, Colombia, Costa Rica, Cyprus, Croatia, Denmark, Finland, Germany, Israel, Latvia, Macedonia, Nigeria, Romania, Serbia, Sweden and the U.K.

Guidry, who’s associated with the identities “k@exploit.im” and “duckylord@priv.in,” was previously investigated within the past year for malicious online activity.

Texas authorities in October raided his home in Liberty Hill — about 35 miles north of Austin — on allegations he attacked a website for a computer repair shop in the capital city, according to his affidavit for arrest.

Guidry, who had been living in Opelousas since May, is scheduled to appear before U.S. Magistrate Judge Patrick Hanna on Friday morning for a bail hearing. He’s been held since Tuesday in the St. Martin Parish jail.

Follow Lanie Lee Cook on Twitter, @lanieleecook, or contact her by phone at (337) 534-0825.