A new wave of cyberattacks has emerged, utilizing the Coyote Banking Trojan to target financial institutions across Brazil. The attack begins with a malicious Windows LNK (shortcut) file, which triggers a stealthy PowerShell command. This command downloads additional payloads from a remote server, starting a multi-stage infection chain that leads to system compromise and data theft. The sophisticated malware employs a variety of techniques, including DLL side-loading and the use of the Squirrel installer framework, to disguise itself as a legitimate update package and avoid detection.
Once executed, the PowerShell script decodes shellcode and injects it into the system’s memory using Windows API functions like VirtualAllocEx and WriteProcessMemory.
The malware ensures persistence by modifying the Windows Registry, allowing it to continue executing even after the system is rebooted. Coyote communicates with its command-and-control (C2) servers over secure SSL channels, sending sensitive system data such as machine names, usernames, and antivirus details to the attackers for further exploitation.
The Coyote Trojan is highly capable, offering features like keylogging, screenshot capturing, and phishing overlays that mimic banking websites to steal sensitive financial information. Additionally, it has the ability to terminate critical processes, block user access with deceptive messages, and even shut down systems entirely. These capabilities make it a serious threat, especially since it is targeting over 70 Brazilian financial institutions and cryptocurrency platforms, actively monitoring and hijacking any banking-related windows or websites.
To defend against such sophisticated threats, experts advise against opening unsolicited LNK files and recommend regularly updating antivirus software to detect such malware. Monitoring the Windows Registry for unauthorized changes and employing endpoint detection tools can also help identify suspicious activity. By remaining vigilant and proactive, organizations can reduce the risk posed by threats like the Coyote Banking Trojan.
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