Called "Gauss," the virus was designed to siphon data from several major Lebanese banks as well as users of CitiBank and PayPal, sending the stolen information back to its still-unknown creator.
It was detected by Kaspersky Lab, the same security firm that found the Flame virus earlier this summer.
Gauss is very similar to Flame -- in fact, it was discovered by Kaspersky exactly because the two share so much DNA. Flame and the new virus have "similar architectural platforms, module structures, code bases and means of communication with command & control (C&C) servers," according to Kaspersky. However, Gauss can infect USB drives in a "more intelligent" fashion, storing collected information in a hidden file on removable drives.
Kaspersky believes Gauss was likely built in the same "factory or factories" as Flame and Stuxnet, both of which also targeted computers in and around the Middle East. However, neither Lebanon nor banking systems were previously considered a target -- Flame and Stuxnet were reported to be products of a secret joint American-Israeli effort targeting Iranian nuclear facilities.
Gauss' exact method of infection, along with some other details about the virus, is not yet known. However, By Kaspersky's estimation, Gauss has already infected tens of thousands of computers -- less than Stuxnet, but more than Flame.
Kaspersky has been tracking Gauss since June, when it was discovered as part of a United Nations-backed effort to reduce the global impact of cyber weapons. It was likely released into the wild in September of last year.