On July 2, 2021, REvil (a.k.a. Sodinokibi), the Russia-affiliated ransomware-as-a-service group, exploited multiple zero-day vulnerabilities in the Kaseya VSA remote monitoring and management IT platform to bypass authentication requirements and deploy the REvil ransomware to numerous organizations using the Kaseya VSA platform.
According to Kaseya, close to 60 of their customers, including some large managed service providers (MSPs), were directly affected by the ransomware attack. However, close to 1,500 downstream businesses have been impacted in total.
Eldon Sprickerhoff, Founder & Chief Innovation Officer at eSentire, says, “Gaining access to admin-level credentials for a remote management solution that distributes software, like Kaseya, and targeting Managed Service Providers is a very efficient way of deploying ransomware to many organizations. Essentially, the MSPs do all the hard work for the threat actors because they unknowingly deploy the malicious software (in this case, the Sodin ransomware dropper) out to all their customers.”
There have also been reports that the REvil group has demanded ransom amounts from victims that range from $50,000 to $5 million based on the size of the corporate networks. Alternatively, they have also stated on their “Happy Blog” that they will publish a universal decryptor in exchange for $70 million in Bitcoin.
As Eldon mentioned, this is not the first time that the Kaseya VSA platform has been compromised. In January 2018, our threat intelligence team discovered threat actors attempting to deploy a Monero cryptocurrency miner to many of our customers.
Like this most recent attack, the threat actors had exploited a zero-day vulnerability within the VSA software solution to gain access to Kaseya’s admin-level credentials. These credentials were then used to help execute an installation bundle that used PowerShell to deploy Monero-mining software to all systems.
“My guess is that in 2018, a threat actor figured out a zero-day in Kaseya, went to Shodan and looked for all external-facing Kaseya instances, built up a bundle to mine Monero, and then en masse started gaining access to these Kaseya installations to deploy their miners,” Eldon added. “This current attack could very well be just a variation on the same attack tactic they used in 2018 which we discovered.”
It’s hard to say whether there are any other parallels between the 2018 Kaseya VSA attack chain and the current cyber attack orchestrated by REvil. As of now, Kaseya has not released any details on how the attack occurred.
Mark Sangster, VP, Industry Security Strategies at eSentire, states, “We don’t know if many of the Kaseya customers, who got hit directly by the REvil attack, were running their Kaseya VSA system on a server which was exposed to the Internet, and if that is how the threat actors identified the Kaseya instances. However, a company should NEVER run any critical application, including an RDP service, on a server that is directly exposed to the Internet. The Kaseya VSA system should be run behind a VPN and at the very least, the organization should restrict the IP addresses that can access it.”
What we know so far…
- Although early reports noted this cyber attack as a supply chain attack, this is no longer the case. It has been confirmed by Kaseya that the REvil threat actors exploited zero-day vulnerabilities in their VSA platform solution.
- Kaseya VSA requires administrator rights, allowing the REvil actors to gain significant privileges on vulnerable systems and deploy ransomware without stealing credentials or escalating privileges.
- There were some noticeable differences compared to past REvil ransomware attacks.
- Currently, there is no indication that REvil used the double-extortion technique as part of their ransom demands.
- Our TRU team has been conducting regular sweeps for all our customers since July 2, based on any indicators of compromise (IOCs) associated with this REvil campaign, in addition to any IOCs known from previous REvil-affiliated campaigns.
- We have taken action to block any REvil-related infrastructure that has been detected from our customers’ environments.
- As of July 8, we have detected only one customer that had the REvil ransomware dropper installed, and we shut their system down before the ransomware could be deployed onto the machine.
Recommendations from our Threat Response Unit (TRU) team
- Download VSA Detection Tool | Powered by Box, the Compromise Detection Tool provided by Kaseya, to detect the presence of known IOCs associated with this campaign within your networks.
- As noted in our July 2 Kaseya security advisory, all on-premises Kaseya VSA servers should be shut down immediately until the Kaseya team releases the vulnerability patch.
- For all VSA on-premises customers, Kaseya has released a runbook to make changes to their on-premises environment to prepare for the patch release.
- Kaseya is also regularly updating their website with the timelines for when organizations can expect the patches.
- Organizations should know exactly what kind of access rights their third-party partners have and implement protocols that limit access into their internal networks. We recognize that access can’t always be limited or restricted. In this case, we recommend:
- Implement network segmentation to inhibit any malicious activity from spreading laterally through the network.
- Provide task-based admin-level permissions to certain individuals when required and immediately revoke those permissions once the task has been completed.
- Never blindly trust any third-party partner or service provider.
- Prioritize rapid patching for any vulnerabilities discovered in Internet-facing products.
- Limit access to critical systems.
- Most importantly, ensure that you have endpoint protections deployed within your IT environment to all desktops and critical servers, to detect the initial intrusion and access. Limiting endpoint monitoring to only desktops is no longer enough.
