Redis servers are being targeted with new malware that deploys a user mode rootkit and cryptocurrency miners, cloud forensics and incident response firm Cado reports.
As part of the observed attacks, threat actors execute a series of commands on the victim Redis servers to disable configuration options and weaken the target before deploying the malicious payload.
According to Cado, the attackers were seen disabling protections that block connections from sources outside the loopback interface and reject incoming write commands, thus opening the door to malware deployment.
The primary payload in these attacks is a piece of malware dubbed ‘Migo’, which is written in the Golang programming language, and which retrieves an XMRig installer from GitHub.
After the miner has been installed and its configuration set, Migo starts querying information about the system, such as the logged-in users and user resource limits.
Cado also noticed the execution of a series of shell commands to make a copy of the binary that will be executed using the persistence mechanism, to disable SELinux, to identify uninstallation scripts for monitoring agents, to execute the miner, to kill competing miner processes, register persistence, and prevent outbound traffic to certain IP addresses and domains.
For persistence Migo relies on a systemd service and an associated timer that executes it every five seconds. The malware also deploys a modified version of a known user mode rootkit, ‘libprocesshider’, which it uses to hide on-disk artifacts.
Additionally, Migo’s developers have taken steps to obfuscate various symbols and strings that could be used for reverse-engineering, as well as to hide malicious processes, Cado notes.
While many of the techniques used in these attacks have been seen in previous incidents involving Redis servers, others are new, showing the threat actors’ ability to evolve.
“The campaign utilized a number of Redis system weakening commands, in an attempt to disable security features of the data store that may impede their initial access attempts. These commands have not previously been reported in campaigns leveraging Redis for initial access,” Cado points out.
Related: P2PInfect: New Peer-to-Peer Worm Targeting Redis Servers
Related: HeadCrab Botnet Ensnares 1,200 Redis Servers for Cryptomining
