A recently observed variant of the Muhstik botnet is exploiting a recently disclosed Oracle WebLogic server vulnerability for cryptomining and distributed denial of service (DDoS) attacks.
Tracked as CVE-2019-2725 and patched last week, the critical vulnerability is a deserialization issue that allows unauthenticated remote command execution, and has been exploited in attacks before a patch was released.
Soon after the vulnerability became public knowledge and proof-of-concept code was made public, security organizations started to observe new attacks targeting it, including the new Sodinokibi ransomware.
According to Palo Alto Networks, a new variant of the Muhstik Linux botnet emerged over the weekend, which attempts to leverage the very same WebLogic flaw to infect systems.
Alive since March 2018 and packing wormlike self-propagating capabilities, Muhstik is known to target Linux servers and Internet of Things (IoT) devices to abuse them for cryptocurrency mining or for DDoS attacks.
The botnet has been observed leveraging multiple exploits for infection purposes, including some targeting WordPress and Drupal vulnerabilities. It even attempted to exploit a previous WebLogic flaw, CVE-2017-10271.
The attacks targeting the new CVE-2019-2725 WebLogic vulnerability feature an exploit payload that includes a shell command to download a .php file from the IP address 165.227.78[.]159. The security researchers say they couldn’t download the payload but that they believe it is a PHP webshell.
Previously, the botnet made use of the IP address 165.227.78[.]159 as a reporting server, to collect information of bots.
“The Oracle WebLogic wls9-async RCE vulnerability is now being used by Muhstik botnet in the wild and there is a great possibility that it will be exploited by other malware families in the future,” Palo Alto Networks concludes.
Related: New Sodinokibi Ransomware Delivered via Oracle WebLogic Flaw
Related: Oracle Patches WebLogic Zero-Day Exploited in Attacks