AWS ransomware attacks: Not a question of if, but when

Ermetic announced the results of a study about the security posture of AWS environments and their vulnerability to ransomware attacks. In virtually all of the participating organizations, identities were found that, if compromised, would place at least 90% of the S3 buckets in an AWS account at risk.

As more and more data moves to the cloud, platforms like AWS are becoming an attractive target for ransomware operators. While Amazon S3 is considered extremely reliable, a compromised identity with the right combination of entitlements can expose data objects to ransomware.

Researchers found that such ransomware-vulnerable combinations are extremely common. In fact, over 70% of the environments in the study had machines that were publicly exposed to the internet and were linked to identities whose permissions could be exploited to allow the machines to perform ransomware.

“Very few companies are aware that data stored in cloud infrastructures like AWS is at risk from ransomware attacks, so we conducted this research to investigate how often the right conditions exist for Amazon S3 buckets to be compromised,” said Shai Morag, CEO of Ermetic.

“We found that in every single account we tested, nearly all of an organization’s S3 buckets were vulnerable to ransomware. Therefore, we can conclude that it’s not a matter of if, but when, a major ransomware attack on AWS will occur.”

Majority of AWS accounts vulnerable to ransomware attacks

Researchers identified the following findings in the organizations they evaluated which would allow ransomware to reach and execute on Amazon S3 buckets:

• Overall, every enterprise environment studied had identities at risk of being compromised and that could perform ransomware on at least 90% of the buckets in an AWS account
• Over 70% of the environments had machines that were publicly exposed to the internet and identities whose permissions allowed the exposed machines to perform ransomware
• Over 45% of the environments had third party identities with the ability to perform ransomware by elevating their privileges to admin level (an astounding finding with far-reaching implications beyond the ransomware focus of this research)
• Almost 80% of the environments contained IAM Users with enabled access keys that had not been used for 180 days or more, and had the ability to perform ransomware

It’s important to note that these findings focus on single, compromised identities. In many ransomware campaigns, bad actors often move laterally to compromise multiple identities and use their combined permissions, greatly increasing their ability to access resources.

“This report highlights the urgent need to “detect threats” in the cloud and not just focus on misconfigurations. Research from Cloud Security Alliance shows that even if misconfigurations are detected in S3 buckets or IAM access keys not being used for a long time, it takes a while for these to get detected and remediated – sometimes days, weeks and even months. It also highlights that ransomware is not just an on-premises problem but as the pandemic has accelerated cloud migration of workloads it has also accelerated cloud migration for attackers and ransomware criminal operators,” Saumitra Das, CTO, Blue Hexagon, told Help Net Security.

Das believes it is critical to monitor 3 things in the cloud:

1. Runtime activity of identities in terms of what they are doing and from where.

2. Cloud storage (S3) in terms of not just the permissions and configurations but actually the read/write pattern and what is actually being stored in there.

3. Network activity which can highlight when instances either inadvertently or deliberately opened to the Internet are brute-forced and then identities stored on those instances are used for lateral movement.