Maverick Banking Trojan Spreads via WhatsApp and Steals Financial Credentials

A new banking Trojan named Maverick has been identified targeting users in Brazil through a sophisticated, fileless malware campaign. The infection chain begins with the distribution of malicious ZIP files containing LNK shortcuts, which are sent via WhatsApp messages. These LNK files are not blocked by WhatsApp, allowing the malware to propagate widely among Brazilian users. Once a device is infected, the Maverick Trojan leverages the open-source WPPConnect project to automate the sending of further malicious messages from the victim’s WhatsApp Web account, effectively turning compromised devices into worms that spread the malware to additional contacts. The Trojan is highly targeted, checking the infected system’s time zone, language, and regional settings to ensure it only installs on Brazilian machines. Upon successful infection, Maverick operates entirely in memory, minimizing disk activity and making detection more difficult. The malware is modular, using PowerShell and .NET components to execute its payloads. Its primary objective is to steal banking and UPI credentials by monitoring browser activity, taking screenshots, logging keystrokes, and overlaying phishing pages when users access banking websites. Maverick can also control the mouse, block the screen during sensitive operations, and terminate processes to evade detection. The campaign specifically targets 26 Brazilian banks, 6 cryptocurrency exchanges, and a major payment platform, indicating a broad financial focus. The command-and-control infrastructure is designed to verify that downloads originate from the malware itself, adding another layer of evasion. Researchers have noted significant code overlap between Maverick and the previously known Coyote Trojan, but Maverick is considered a distinct and new threat. The use of WhatsApp as a distribution vector is particularly concerning, as it exploits the trust between contacts and the widespread use of the messaging platform in Brazil. The fileless nature of the attack chain, combined with the use of legitimate open-source tools, complicates detection and remediation efforts. Security experts recommend heightened vigilance for suspicious WhatsApp messages containing attachments, especially those in Portuguese or referencing financial matters. Organizations and individuals are urged to update their security solutions and educate users about the risks of opening unsolicited files, even from known contacts. The emergence of Maverick underscores the evolving tactics of cybercriminals targeting the Brazilian financial sector and highlights the need for robust, multi-layered defenses.