The Coyote malware stands as a stark manifestation of cybercriminal innovation, with a direct focus on over sixty financial institutions within Brazil’s borders. Deviating from traditional banking malware, which typically resides on Delphi or MSI installers, Coyote adopts cutting-edge programming languages like Node.js, .NET, and Nim. This strategic choice exemplifies the ongoing evolution of cybercriminal tactics designed to penetrate advancing security defenses more effectively. With its intricate methods of infiltration, Coyote malware showcases the increasingly complex and inventive nature of today’s cyber threats.
The Inception of Infection
At the core of Coyote malware’s strategy is an infection chain that is as devious as it is effective. Utilizing a Squirrel installation package, commonly employed in Windows app updates, Coyote uses an element of disguise to start its infection process. The Squirrel platform is typically not associated with malicious intent, allowing Coyote to seamlessly introduce Node.js based applications under the radar. This initial step is crucial as it plants the malicious payload onto the victim’s system in a manner that appears innocuous, leveraging everyday tools to ingrain itself into target systems with meticulous precision.
The false sense of security is short-lived as the malware continues its advance, sneakily inserting a loader into the host’s directory. This loader paves the way for a .NET executable to run directly from memory, reminiscent of methods used by the Donut exploitation technique. The aim is to execute the malicious code while minimizing traces on the system’s storage, thus evading traditional file-based antivirus measures.
Stealth and Extraction Protocols
The threat posed by Coyote malware is not only in its execution but also in its approach to remaining undercover. Rather than utilizing conspicuous code obfuscation techniques, Coyote opts for AES encryption, embedding itself into the host machine with distinct initialization vectors and utilizing Windows login scripts for persistence. Its attack vector is precise, triggering only in the presence of banking operations to stealthily connect with its command-and-control (C2) server and commence its data exfiltration mission. This includes capturing keystrokes and screenshots to acquire sensitive banking credentials.
The malware’s communication is meticulously shielded—covered by SSL channels that include mutual authentication, further emphasizing Coyote’s complexity in avoiding detection. The strategic decryption of C2 server certificates further demonstrates the malware’s advanced capabilities. Solely focusing on Brazilian banks, Coyote represents an alarmingly tailored and stealthy approach in the constantly evolving sphere of cyber threats, emphasizing the critical need for organizations and their cybersecurity frameworks to adapt to such targeted threats.