Eastern European crackers have spent a year systematically exploiting known NT vulnerabilities to raid online banking and ecommerce systems.
More than 40 companies have been subject to attacks and it is believed more than a million credit cards have been stolen, provoking the FBI to take the highly unusual step of providing details of an ongoing investigation in the hopes of limiting further damage.
The FBI's National Infrastructure Protection Center and Microsoft have both issued alerts advising users to bolt up their security hatches.
Users have been advised to check systems for protection against specific vulnerabilities, some of which were fixed as long ago as 1998.
The FBI advisory, which follows on from similar advice issued in December last year, notes "the FBI has continued to observe hacker activity targeting e-commerce or e-finance/banking businesses which, in many cases, had been ongoing for several months before the victim became aware of the intrusion."
According to the FBI, the investigative trail has led to "several organised hacker groups from Eastern Europe, specifically Russia and the Ukraine, that have penetrated US e-commerce computer systems by exploiting vulnerabilities in unpatched Microsoft Windows NT operating systems."
Once the hackers gain access to systems they download proprietary information, customer databases, and credit card information before trying to blackmail victims. This involves a form of protection rackets where the criminal crackers pose as "good guys" who offer security services to patch the system against other hackers.
"They tell the victim that without their services, they cannot guarantee that other hackers will not access the network and post the credit card information and details about the compromise on the Internet," the FBI reports.
The FBI and Microsoft have drawn up a series of recommendations of key vulnerabilities associated with the attacks, which in many cases, systems administrators have repeatedly failed to address.
These cover flaws which allows unauthorised users to execute shell commands on IIS systems, a SQL vulnerability, a registry permissions bug and a Web server file parsing flaw. Links to patches for these flaws, and further advice, is available from Microsoft here ®