The threat actor behind the BlackRock and ERMAC Android banking trojans has unleashed yet another malware for rent called Hook that introduces new capabilities to access files stored in the devices and create a remote interactive session.
ThreatFabric, in a report shared with The Hacker News, characterized Hook as a novel ERMAC fork that's advertised for sale for $7,000 per month while featuring "all the capabilities of its predecessor."
"In addition, it also adds to its arsenal Remote Access Tooling (RAT) capabilities, joining the ranks of families such as Octo and Hydra, which are capable performing a full Device Take Over (DTO), and complete a full fraud chain, from PII exfiltration to transaction, with all the intermediate steps, without the need of additional channels," the Dutch cybersecurity firm said.
A majority of the financial apps targeted by the malware are located in the U.S., Spain, Australia, Poland, Canada, Turkey, the U.K., France, Italy, and Portugal.
Hook is the handiwork of a threat actor known as DukeEugene and represents the latest evolution of ERMAC, which was first disclosed in September 2021 and is based on another trojan named Cerberus that had its source code leaked in 2020.
"ERMAC has always been behind Hydra and Octo in terms of capabilities and features," ThreatFabric researcher Dario Durando told The Hacker News via email. "This is also known among threat actors, who prefer these two families above ERMAC."
"The lack of some sort of RAT capabilities is a major issue for a modern Android Banker, as it does not provide the possibility to perform Device Take Over (DTO), which is the fraud methodology that is most likely to be successful and not detected by fraud scoring engines or fraud analysts. This is most likely what triggered the development of this new malware variant."
Like other Android malware of its ilk, the malware abuses Android's accessibility services APIs to conduct overlay attacks and harvest all kinds of sensitive information such as contacts, call logs, keystrokes, two-factor authentication (2FA) tokens, and even WhatsApp messages.
It also sports an expanded list of targeted apps to include ABN AMRO and Barclays, while the malicious samples themselves masquerade as the Google Chrome web browser to dupe unsuspecting users into downloading the malware:
- com.lojibiwawajinu.guna
- com.damariwonomiwi.docebi
- com.yecomevusaso.pisifo
Among the other major features to be added to Hook is the ability to remotely view and interact with the screen of the infected device, obtain files, extract seed phrases from crypto wallets, and track the phone's location, blurring the line between spyware and banking malware.
ThreatFabric said the Hook artifacts observed so far in a testing phase, but noted it could be delivered via phishing campaigns, Telegram channels, or in the form of Google Play Store dropper apps.
"The main drawback of creating a new malware is usually gaining enough trust by other actors, but with the status of DukeEugene among criminals, it is very likely that this will not be an issue for Hook," Durando said.
