Alibaba ECS instances targeted in new cryptojacking campaign
ECS instances come with a preinstalled security agent that hackers try to uninstall upon compromise. Researchers said specific code in the malware created firewall rules to drop incoming packets from IP ranges belonging to internal Alibaba zones and regions.
These default Alibaba ECS instances also provide root access. The problem here is these instances lack the different privilege levels found in other cloud providers. This means hackers who gain login credentials to access a target instance can do so via SSH without mounting an escalation of privilege attack beforehand.
“In this situation, the threat actor has the highest possible privilege upon compromise, including vulnerability exploitation, any misconfiguration issue, weak credentials, or data leakage,” said researchers.
This enables advanced payloads, such as kernel module rootkits, and achieving persistence via running system services to be deployed. “Given this feature, it comes as no surprise that multiple threat actors target Alibaba Cloud ECS simply by inserting a code snippet for removing software found only in Alibaba ECS,” they added.
Researchers said that when crypto-jacking malware is running inside Alibaba ECS, the security agent installed will send a notification of a malicious script running. It is then up to the user to prevent ongoing infection and malicious activities. Researchers said it is always the responsibility of the user to prevent this infection from happening in the first place.
“Despite detection, the security agent fails to clean the running compromise and gets disabled,” they added. “Looking at another malware sample shows that the security agent was also uninstalled before it could trigger an alert for compromise.”
Once compromised, the malware installs an XMRig to mine for Monero.
Researchers said it was important to note that Alibaba ECS has an auto-scaling feature to automatically adjust computing resources based on the volume of user requests. This means hackers can also scale up crypto mining and with users bearing the costs.