Nine people connected to the "Zeus" malware have been indicted, federal officials announced Friday as they declared the code "one of the most damaging pieces of financial malware that has ever been used."

An indictment (PDF) unsealed Friday charges nine people, most of them from the Ukraine. Two defendants—Yuriy Konovalenko, 31, and Yevhen Kulibaba, 36—were extradited to the United States and hauled Friday into Nebraska federal court, where the charges were unsealed. Most of the others remain at large.

The authorities said the defendants used Zeus to hijack account numbers, passwords, personal identification numbers, RSA SecureID token codes, and other data needed to illegally log in to online banking accounts, netting the defendants "millions of dollars." Prosecutors said they were responsible for "infecting thousands of business computers with malicious software."

According to the Justice Department, Kulibaba allegedly ran "the conspirators' money laundering network in the United Kingdom by providing money mules and their associated banking credentials to launder the money withdrawn from US-based victim accounts." Konovalenko, the government said, allegedly "provided money mules' and victims' banking credentials to Kulibaba and facilitated the collection of victims' data from other conspirators."

First seen in 2007, bots based on Zeus have infected millions of computers globally. A 2010 study by network security company RSA concluded that almost all Fortune 500 companies showed evidence of some form of a Zeus botnet infection.

Zeus provides do-it-yourself cybercriminals with the platform to configure, package, and manage botnets and then dynamically reconfigure them once they've been deployed. Zeus is generally designed to develop distributed attack packages, ranging from keylogging to sophisticated Web session hijacking attacks called "Web injects."

Zues was being sold as a commercial product for as much as $700. Its source code was published in several hacker forums in 2011.

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