The code, dubbed Trj/Briz.A by PandaLabs, stands out because its author customizes the code for hackers. The malware specializes in stealing bank details and data from web forms.
According to PandaLabs, this trojan is "the most complex example of the business network based on malware."
Apart from the code, cyber-crooks that buy this crimeware also get a complex system for controlling the infection caused by the custom-built trojan. This allows the client to get a list containing a large quantity of data about the infected computers: IP addresses, passwords and even the physical location of the computers.
In this way, the cyber-crooks can always have their malicious activity under control.
The file that causes the Trj/Briz.A infection is called "iexplore.exe." It uses this name to pass itself off as Internet Explorer. When run, it downloads different files and deactivates Windows Security Center services and Shared Internet Access. It also collects information on programs like Outlook, Eudora and The Bat, which it sends to the attacker.
To make it difficult to detect and disinfect the trojan, it also modifies the hosts file to prevent access to websites related to antivirus products.
Luis Corrons, director of PandaLabs, said that whereas hackers used to create malicious code to simply have fun, they now have direct financial goals, designing their creations based on a criminal business model.
"As authors of internet threats have changed their objective, which is now financial gain, they have also changed the way they design their threats. Therefore, they try to ensure that their creations go unnoticed, to both users and security companies, for as long as possible."