A two-year investigation of the creator and operators of the Mariposa Botnet by the FBI, in partnership with the Slovenian Criminal Police and the Spanish Guardia Civil is bearing fruit.

The Mariposa Botnet -- a network of remote-controlled compromised computers -- was built with a computer virus known as "Butterfly Bot" and was used to steal passwords for websites and financial institutions. It stole computer users' credit card and bank account information, launched denial of service attacks, and spread viruses. Industry experts estimated the Mariposa Botnet may have infected as many as 8 million to 12 million computers.

"In the last two years, the software used to create the Mariposa Botnet was sold to hundreds of other criminals, making it one of the most notorious in the world," said FBI Director Robert S. Mueller, III. "These cyber intrusions, thefts, and frauds undermine the integrity of the Internet and the businesses that rely on it; they also threaten the privacy and pocketbooks of all who use the Internet."

International effort

In February, the Spanish Guardia Civil arrested three suspected Mariposa Botnet operators: "Netkairo," "Jonyloleante," and "Ostiator," aka Florencio Carro Ruiz, Jonathan Pazos Rivera, and Juan Jose Bellido Rios. They are being prosecuted in Spain for computer crimes.

"The Mariposa case showed how the coordinated and joint actions of different international police forces, along with the efforts of the Internet security industry, have been able to face the global threat of cyber crime," said Maj. Juan Salom, commander of the Guardia Civil's Cyber Crime Division. "The cyber kingpins know that they are not invincible anymore because the global efforts of the FBI, Slovenian Criminal Police, and Spanish Guardia Civil have shown that it doesn't matter where or how they try to hide, they will be located and prosecuted."

Last week, the Slovenian Criminal Police identified and arrested the Mariposa Botnet's suspected creator, a 23-year-old Slovenian citizen known as "Iserdo." The work of the Slovenian and Spanish authorities was integral to this investigation, officials said.

"We are glad to cooperate with the United States; the FBI's assistance is invaluable and represents professional affirmation of our force," Slovenian Minister of the Interior Katarina Kresal and Director General Janko Gorsek, Slovenian Criminal Police, said in a statement. "This case shows that cyber crime issues call for international police cooperation that shouldn't be hindered by geographical borders. This partnership serves as a solid basis for future cooperation."

From 2008 to 2010, the Slovenian citizen created "Butterfly Bot" and sold it to other criminals worldwide. In turn, these criminals developed networks of infected computers -- botnets -- and the Mariposa variety from Spain was the most notorious and largest. In addition to selling the Butterfly Bot program, the Slovenian citizen developed customized versions for certain customers and created and sold plug-ins (add-ons) to augment the botnet's features and functionality.

"This case shows the value of strong partnerships among law enforcement agencies worldwide in the fight against cyber criminals", said FBI Cyber Division Assistant Director Gordon M. Snow. "Cyber crime knows no boundaries, and without international collaboration, our efforts to dismantle these operations would be impossible."