TeamTNT, a notorious hacking group, has resurfaced with a new cryptojacking campaign targeting CentOS-based Virtual Private Servers (VPS). According to a report by researchers at Group-IB, the campaign begins with brute-force attacks on Secure Shell (SSH) services, allowing attackers to upload malicious scripts to compromised systems. These scripts disable essential security features, delete logs, and terminate any existing cryptocurrency mining processes, paving the way for further exploitation.
The malicious scripts are designed to deploy the Diamorphine rootkit, which conceals the attackers’ activities and establishes persistent remote access to the infected servers. By compromising the integrity of the system, the attackers can execute their cryptojacking operations without detection. This return of TeamTNT highlights the persistent threat of such cryptojacking activities in cloud and container environments, particularly for organizations using CentOS.
TeamTNT first emerged in 2019, focusing on illicit cryptocurrency mining within cloud infrastructures. Although the group announced a “clean quit” in November 2021, subsequent reports have linked them to several campaigns since September 2022. The latest activity showcases their evolving tactics, including a shell script that checks for previous infections and disables crucial security measures like SELinux, AppArmor, and firewalls to facilitate their malicious operations.
Furthermore, the script implements a series of commands to eliminate traces left by competing miners and establishes persistence through scheduled cron jobs. By modifying SSH configurations and creating backdoor accounts, the attackers ensure continued access to compromised systems. As the threat landscape continues to evolve, cybersecurity experts emphasize the need for robust security measures to defend against such cryptojacking campaigns and protect sensitive infrastructure from exploitation.
