Unit 42 cybersecurity researchers have recently identified a new post-exploitation red team tool known as Splinter, which has raised significant concerns in the cybersecurity community. Developed in Rust, a programming language recognized for its memory safety features, Splinter has been discovered on multiple customer systems, emphasizing the urgent need for organizations to enhance their detection and tracking capabilities for such tools. The emergence of Splinter highlights the increasing sophistication of cyber threats and the diverse array of tools available to threat actors.
Splinter is designed to simulate long-term access to compromised systems, effectively expanding initial access gained through various exploitation techniques. The tool operates using a configuration data structure in JSON format, termed ImplantConfig, which contains critical information such as the implant ID, targeted endpoint ID, command and control (C2) server address, and login credentials. This structured approach allows attackers to execute a variety of tasks remotely, including executing Windows commands, uploading and downloading files, and even gathering sensitive information from cloud service accounts.
One of the standout features of Splinter is its use of classic process injection methods, which enable it to run additional modules by injecting payloads into remote processes. This capability allows for a stealthier operation, making detection more challenging for cybersecurity teams. The tool’s relatively large size—approximately 7 MB—is attributed to the inclusion of multiple large external libraries, known as crates in Rust, which provide various networking and encryption functionalities. This complexity, combined with its encrypted communication with the C2 server via HTTPS, complicates the detection and blocking of Splinter’s activities.
While Splinter may not yet rival established post-exploitation tools like Cobalt Strike in terms of sophistication, its discovery serves as a critical reminder for organizations to remain proactive in their cybersecurity efforts. The evolving threat landscape necessitates continuous monitoring and updating of security measures to combat emerging tools like Splinter. As cyber threats become increasingly complex, it is essential for organizations to stay informed and equipped to mitigate potential risks posed by such advanced tools, thereby safeguarding their networks and sensitive data from exploitation.
