The cryptojacking operation often known as TeamTNT has probably resurfaced as a part of a brand new marketing campaign concentrating on Digital Non-public Server (VPS) infrastructures based mostly on the CentOS working system.
“The preliminary entry was completed by way of a Safe Shell (SSH) brute pressure assault on the sufferer’s property, throughout which the risk actor uploaded a malicious script,” Group-IB researchers Vito Alfano and Nam Le Phuong stated in a Wednesday report.
The malicious script, the Singaporean cybersecurity firm famous, is chargeable for disabling safety features, deleting logs, terminating cryptocurrency mining processes, and inhibiting restoration efforts.
The assault chains finally pave the best way for the deployment of the Diamorphine rootkit to hide malicious processes, whereas additionally organising persistent distant entry to the compromised host.
The marketing campaign has been attributed to TeamTNT with average confidence, citing similarities within the techniques, methods, and procedures (TTPs) noticed.
TeamTNT was first found within the wild in 2019, endeavor illicit cryptocurrency mining actions by infiltrating cloud and container environments. Whereas the risk actor bid farewell in November 2021 by saying a “clear give up,” public reporting has uncovered a number of campaigns undertaken by the hacking crew since September 2022.
The newest exercise linked to the group manifests within the type of a shell script that first checks if it was beforehand contaminated by different cryptojacking operations, after which it precedes to impair machine safety by disabling SELinux, AppArmor, and the firewall.
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| Adjustments carried out on ssh service |
“The script searches for a daemon associated to the cloud supplier Alibaba, named aliyun.service,” the researchers stated. “If it detects this daemon, it downloads a bash script from replace.aegis.aliyun.com to uninstall the service.”
In addition to killing all competing cryptocurrency mining processes, the script takes steps to execute a collection of instructions to take away traces left by different miners, terminate containerized processes, and take away photographs deployed in reference to any coin miners.
Moreover, it establishes persistence by configuring cron jobs that obtain the shell script each half-hour from a distant server (65.108.48[.]150) and modifying the “/root/.ssh/authorized_keys” file so as to add a backdoor account.
“It locks down the system by modifying file attributes, making a backdoor consumer with root entry, and erasing command historical past to cover its actions,” the researchers famous. “The risk actor leaves nothing to likelihood; certainly, the script implements numerous modifications inside the SSH and firewall service configuration.”