Security researchers at NetWitness have discovered a massive botnet known as Kneber that has affected at least 75,000 computers at 2,500 companies and government agencies worldwide for the past 18 months, Computerworld reports.
NetWitness says Kneber used the Zeus Trojan to collect login credentials to online financial systems, social networking sites and e-mail systems. Among the companies affected are pharmaceutical giant Merck & Co., Cardinal Health Inc., Paramount Pictures and software company Juniper Networks Inc., according to The Wall Street Journal.
CNET News says NetWitness believes that criminals in Eastern Europe sent attachments containing the malware in e-mails or links to the malware on Web sites that tricked employees within the companies to click on them. Most of the infections were found in Egypt, Mexico, Saudi Arabia, Turkey and the United States.