Researchers are warning that a well-known banking trojan is evolving into something even more insidious. The Brazilian Remote Access Tool, Android (BRATA) has been around in some form since 2019, and will intercept two-factor SMS codes and steal other device information that can be used to take over someone’s bank account.
BRATA is also famous for the extreme measures it takes to avoid detection. Once the fraudster has hacked into an account and completed a transaction, BRATA will wipe the victim’s phone using the Android factory reset setting. The reset prevents the victim from learning about and reporting the fraudulent transfer while there is still time to stop the exchange. The trojan (which only infects Android devices) will similarly trigger a factory reset if it is spotted by any security software that may be running on the victim’s phone.
The new version of BRATA is being distributed across more platforms, and is able to extract even more data before it decides to cover its tracks. With regards to the former, BRATA has historically been circulated through SMS messages that mimic messages from the target’s bank. Those messages contain a link that will install BRATA if the victim opens it. The updated BRATA, on the other hand, has been left sitting on webpages that are designed to look like a real banking website to phish for additional clicks.
On the harvesting front, the enhanced BRATA (which was initially developed as spyware before morphing into a trojan) can ask users to switch from their phone’s default messaging app to a new one that remains under the fraudster’s control. That allows the fraudster to intercept any messages (including One-Time Passcodes) that come through. BRATA also lets fraudsters obtain device management permissions, gather GPS location data, and install a secondary piece of malware that logs events on the victim’s phone.
The mutated BRATA was discovered by a team of researchers from the Italian cybersecurity firm Cleafy. In addition to BRATA, they warned that there is another piece of malware that has some of the same code that seems as if it was built to collect contact information from an infected device. BRATA itself has primarily been used to target customers of banks in Brazil, the UK, and Spain, though the people using it are only targeting a single financial institution at a time. The fraudsters move on once that financial institution starts to implement stronger fraud prevention measures, but may circle back later with more sophisticated malware.