The threat actors behind the Windows banking malware known as Casbaneiro has been attributed as behind a novel Android trojan called BrasDex that has been observed targeting Brazilian users as part of an ongoing multi-platform campaign.
BrasDex features a “complex keylogging system designed to abuse Accessibility Services to extract credentials specifically from a set of Brazilian targeted apps, as well as a highly capable Automated Transfer System (ATS) engine,” ThreatFabric said in a report published last week.
The Dutch security firm said that the command-and-control (C2) infrastructure used in conjunction with BrasDex is also being used to control Casbaneiro, which is known to strike banks and cryptocurrency services in Brazil and Mexico.
The hybrid Android and Windows malware campaign is estimated to have resulted in thousands of infections to date.
BrasDex, which masquerades as a banking app for Banco Santander, is also emblematic of a new trend that involves abusing Android’s Accessibility APIs to log keystrokes entered by the victims, moving away from the traditional method of overlay attacks to steal credentials and other personal data.
It’s also engineered to capture account balance information, subsequently using it to take over infected devices and initiate fraudulent transactions in a programmatic manner.