On Friday morning, the RSA Fraud Action Research Lab reported that it had uncovered a digital cache of more than half million credit card numbers and online bank account login and passwords. The accounts have been acquired during the past two-and-a-half years by what the researchers believed to be a Russian online gang.

The cache of stolen information was created by Sinowal Trojan, also known as Torpig and Mebroot. Sinowal Trojan is a kind of Trojan Horse that takes information from users after they have taken over their system. The Trojans are usually distributed by botnets, a network of zombie computers made for the sole purpose of infecting others with the Trojan.

Sinowal is particularly insidious because it is technically sophisticated. The creators of the Sinowal trojan have been periodically releasing new variants and extending the Internet domains that supports the program, making its effect extensive and hard to crackdown. The program has the ability to present users with false web pages that can falsely prompt an unsuspecting victim for personal information such as a social security number or other personal information. The program watches for particular financial Web pages and then launches itself into action to capture personal information.

This diagram below shows the rate at which the creators of the Sinowal Trojan have been creating new variants.

In the past six months, Sinowal Trojan has compromised more than 100,000 online bank accounts. The diagram below shows the rate at which Sinowal has been compromising online bank accounts.

Sinowal Trojan is maybe the worst trojan ever created in history for compromising hundreds of thousands bank accounts.