Authorities in Bulgaria arrested eight people last week who allegedly stole financial information using a variety of fake web pages carrying Microsoft logos, netting the group at least £28,000.
The group, known as the MBAM (Microsoft Billing Account Management) gang, launched 46 attacks on 43 compromised servers in 11 countries, Microsoft said in a news release on Saturday. Using a technique known as phishing, the group sent fraudulent emails purporting to be from MSN's customer service team asking recipients to update their account information.
Microsoft said it assisted NSCOC, Bulgaria's National Service for Combating Organised Crime, with investigative and technical support. Raids were conducted in three cities in Bulgaria, the firm said.
The group set up dozens of lookalike web pages similar to MSN websites asking for personal identification and verification numbers. The group then used the stolen data – from credit card holders in the UK, Germany and the US – for purchases and money transfers, Microsoft said.