The U.S. has disrupted a global network of infected computers known as the Gameover Zeus Botnet, which was used by criminals to spread malware and steal millions of dollars from businesses and consumers, the Justice Department announced Monday.

In a separate action, U.S. and foreign law enforcement officials also seized control of the malware known as Cryptolocker, which locks victims out of their computer files until they pay a ransom.

The FBI estimates that Gameover Zeus, which first emerged around September 2011, is responsible for more than $100 million in losses. "Gameover Zeus is the most sophisticated botnet the FBI and our allies have ever attempted to disrupt," FBI Executive Assistant Director Robert Anderson said in a statement.

A 14-count indictment, unsealed Monday in Pittsburgh, charges Evgeniy Mikhailovich Bogachev, 30, of Anapa, Russia with overseeing the Gameover Zeus botnet. Bogachev, who was linked the online aliases "Slavik" and "Pollingsoon," was allegedly the leader of a gang of cybercriminals based in Russia and Ukraine responsible for the development and operation of both Gameover Zeus and Cryptolocker.

Charges against Bogachev include conspiracy, computer hacking, wire fraud, bank fraud, and money laundering. He was also separately charged in Omaha with conspiracy to commit bank fraud for alleged involvement in an older variant of Zeus malware called "Jabber Zeus." Bogachev remains at large.

The Gameover Zeus malware, also known as "Peer-to-Peer Zeus," is designed to steal banking credentials and other information from infected computers, and rope them into a global network of compromised machines known as a botnet. Between 500,000 and 1 million computers worldwide are infected with Gameover Zeus, approximately 25 percent of which are located in the U.S.

Gameover Zeus is also commonly used to distribute the Cryptolocker malware, which first emerged in Sept. 2013 and encrypts files on a victims' computer. Scammers demand that users pay as much as $700 or more to receive the key necessary to unlock their files.

As of April, Cryptolocker had infected more than 234,000 computers, approximately half of which are located in the U.S. Victims paid an estimated $27 million in ransom payments in the first two months since the malware emerged.

As part of the cleanup effort, federal agents have redirected infected computers to Homeland Security servers to identify victims and provide information about how to remove the malware. Victims can head over to the DHS's Computer Emergency Readiness Team (US-CERT) website for assistance.

The latest cybercrime enforcement action comes after the feds in April announced charges against nine individuals who allegedly used Zeus as part of a "wide-ranging racketeering enterprise" to break into business computers and steal millions of dollars from victims' bank accounts.