Trojans are malicious applications that pose themselves as legitimate software in order to trick users to install them. Once on the victim's machine, it may run any number of malicious process to steal vital information or inflict damage to other software.
File claims to be a VISA statement, hosted at a site sent via an email link. When executed, the ZBot Trojan is activated. The file sdra64.exe is added to the System43 directory, and is known as a keylogger and banking theft infection file.