Dubbed the "MBAM Gang" by Microsoft -- for Microsoft Billing Account Management, the purported source of the phishing messages -- the group allegedly sent e-mails with spoofed MSN customer support addresses to dupe recipients into divulging credit card information. According to Bulgaria's National Services to Combat Organized Crime (NSCOC) agency, the stolen account data was used to purchase goods and make wire transfers of more than $50,000 from U.S., German, and British credit cards.
Microsoft said that it had handed over information about the attacks to the NSCOC, and provided technical assistance during the investigation.
"We are pleased to have collaborated with the Bulgarian authorities in their swift and effective action in this case," said Horacio Gutierrez, associate general counsel for Microsoft Europe, in a statement.
"Microsoft believes vigorous criminal enforcement against phishers is essential to show cybercriminals that there are consequences to their illegal actions," he added.