Swiping CPU cycles from Kubernetes container clusters to mine crypto-coins is the latest rage among cybercrooks.
So says Swiss security intelligence house BinaryEdge, which reckons it has spotted multiple instances of vulnerable clusters being taken over and then used to run scripts that mine cryptocurrencies for the attackers.
While coin-mining malware has long been a popular tool for hackers to generate cash using other people's hardware, most of the attacks seen so far have focused on running mining code on victims' PCs or by injecting mining scripts into webpages on popular websites and stealing CPU cycles from everyone who visits.
Container clusters, however, could be an attractive target to scumbags as the machines powering the containers are usually servers with a lot of oomph which means more coins can be dug up per hour, and in a busy environment, it may not be easy to spot crafty coin-mining malware right away.
Although vulnerability disclosures have brought Kubernetes security to the forefront as of late, BinaryEdge says the attacks they are seeing are far simpler: many of the infected clusters required no exploit, but rather were accidentally left wide open to the public internet.
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"As is typical with our findings, lots of companies are exposing their Kubernetes API with no authentication; inside the Kubernetes cluster, small containers called Pods are ran. Essentially a pod represents a process inside the cluster," the security biz explained this week.
"By having this exposed, an attacker can not only see what is running on the Pods but also execute commands on the Pods themselves. The result is that we are seeing worldwide many Kubernetes clusters having their Pods hijacked to mine cryptocurrencies."
In one example, BinaryEdge showed that a pod had been sent a curl command to fetch a .json that ran the Cryptonight mining code. The researchers noted that the exposed APIs could have consequences far beyond lost CPU cycles, as an attacker who had enough access to run coin-mining scripts could likely access other services and sensitive data, and perform other misdeeds.
The infections are not just limited to isolated instances either, as BinaryEdge says its researchers have found infected clusters in all sorts of organizations, from large enterprises to small businesses.
Admins would be well advised to make sure their APIs are properly secured and not accessible to the open internet. And try using some monitoring scripts to detect unexpected workloads. ®