Description

A recent and targeted cyberattack using the DCRat Remote Access Trojan (RAT) has been identified by Fortinet researchers, aimed at compromising organizations in Colombia. The threat actors disguise their messages to appear as official government communications, delivering phishing emails containing password-protected ZIP attachments. These deceptive messages use the BCC field to obscure the list of recipients. Upon opening the archive, a batch file launches, which in turn downloads a heavily obfuscated VBS script from a public paste site. This script contains hidden code that extracts and executes a payload embedded in an image file using steganography. After completing the infection process, the malware downloads a RAT executable from a spoofed URL and unlocks it using a predefined AES256 encryption key. DCRat’s modular framework enables attackers to install additional malicious components based on their specific goals. Its functions include full remote access, file and process manipulation, browser and credential theft, keylogging, and screen capturing. It can also alter system behavior, such as initiating forced reboots, changing desktop settings, or creating new accounts. Furthermore, it can crash the system by marking itself as a critical process when stopped. For persistence, DCRat modifies the Windows registry or sets up scheduled tasks to restart itself automatically. It further disables the Windows Antimalware Scan Interface (AMSI) by patching its memory space, allowing it to avoid detection. To maintain an active link with its command-and-control (C2) server located at `176.65.144.19:8848`, the malware enters an infinite loop, ensuring continuous interaction and potential future exploitation by threat actors. Fortinet's security ecosystem—which includes FortiMail, FortiClient, FortiGate, and FortiEDR—effectively identifies the DCRat threat, flagged under the detection name “MSIL/Agent.CFQ!tr”. FortiGuard services further bolster defenses by neutralizing harmful content and tracking suspicious IP behavior.