A fresh wave of cyberattacks exploiting Bomgar remote monitoring and management (RMM) instances has hit various organizations and their customers over the past two weeks, sparking concerns about further attacks on unpatched systems that can have a rapid downstream effect on the supply chain.
Researchers at Huntress Security Operations Center (SOC) observed what they call “a sharp uptick” in exploitation activity targeting Bomgar Remote Support (now part of BeyondTrust), with attackers reaching systems through a critical unauthenticated remote code execution (RCE) flaw, CVE-2026-1731, according to a recent blog post from the team.
“This most recent uptick in Bomgar-related incidents follows an initial wave of attacks observed by the SOC in February, when CVE-2026-1731 was first disclosed,” Huntress tactical response analyst Josh Allman wrote in the post. The flaw in BeyondTrust Remote Support and older versions of the vendor’s Privileged Remote Access (PRA) allows unauthenticated attackers to craft requests that can execute arbitrary operating system commands remotely.
“Keys to the Kingdom”
The recent spate of attacks demonstrates how quickly attackers can use the initial compromise to move to other organizations and quickly spread across the supply chain. For example, one attack on April 3 compromised a dental software company and affected three downstream companies. Another attack on April 15 affected a managed service provider (MSP) and “led to the mass isolation of 78 businesses and subsequent exploitation across four downstream customers,” Allman wrote.
“Targeting the server running the RMM appliance is like getting the key to the city,” he tells Dark Reading via email. “Once they have access to this upstream server, the attacker has access to all the downstream clients.” This is especially dangerous when it’s a software vendors support client or an IT providers clients, as they will have hundreds, if not thousands, of clients across multiple organizations the attacker gets access to by just exploiting the server, Allman adds.
Some of the incidents involved the deployment of LockBit ransomware, while in others attackers engaged in reconnaissance, privilege escalation, the execution of other RMMs such as AnyDesk and Atera, and other malicious activity. In ransomware deployments, Huntress believes the threat actors used the previously leaked LockBit 3.0 builder, Allman noted in the report.
RMMs Under Attack
Overall, the recent incidents demonstrate threat actors’ continued shift toward exploiting RMMs rather than using traditional malware. This type of compromise of tools that are nearly ubiquitous in enterprise environments gives them a stealthy and efficient way to compromise not only organizations but also move laterally to their customers and partners for further attacks.
Huntress observed five recent incidents attacking Bomgar RMM instances in the past two weeks, starting with the one on April 3 that dropped Atera for persistence. Another attack on April 5 also used an RMM — AnyDesk — for persistence, conducted enumeration activities, and added the user to the Local/Domain admin groups.
An attack on April 12 was the first of these recent attacks to deploy LockBit ransomware, with analysts observing “a rogue Bomgar RMM instance being used to gain access to endpoints, which resulted in successful ransomware execution on the network,” Allman wrote. “Here, we also saw threat actors use the rogue RMM instance to create and add a new user to the Local Administrators Group,” he added.
There were two separate attacks on April 14, with threat actors deploying an RMM in both — AnyDesk in one instance and Atera in the other. Both attacks also saw the threat actors adding users to admin groups, pointing to a show of persistence on the network, Allman noted. The attack that used AnyDesk also deployed LockBit ransomware.
Overall, the attacks demonstrated a pattern of actors targeting high-privilege Bomgar accounts within MSP environments and pushing access tools directly onto domain controllers, according to Huntress. From there, they can entrench themselves and expand laterally into customer networks with minimal resistance.
Defenders, Take Immediate Action
Given that the attack entry point is a known vulnerability and that the incidents are ongoing, they demonstrate once again how important it is for organizations to patch vulnerable systems, which is the first recommendation Huntress made to avoid compromise. And with the recent surge in interest by attackers in exploiting RMMs —particularly for the deployment of ransomware — patching these systems is especially important.
And though it’s unclear who’s behind the attacks, which Huntress did not reveal in its report, there has been a previous connection between the Lockbit ransomware gangs and the use of RMMs to spread their foothold in a victim network. Several years ago, a spate of attacks by a LockBit affiliate either took advantage of exposed RMM instances, or used their own RMM during the attack to cement the group’s footing in victim networks. These attacks also demonstrated how threat actors are bypassing malware in favor of using RMM tools or other living off the land (LotL) tactics to make it more difficult for security professionals and analysts to detect malicious activity.
That’s yet another reason for defenders to monitor closely for suspicious activity related to the malicious use of legitimate RMMs in their environments, according to Huntress. Other ways to do this are to monitor for unauthorized administrator accounts and for unexpected RMM tool deployment, and to investigate suspicious activity tied to Bomgar processes. Huntress also included a list of indicators of compromise (IOCs), including various executables, used in the attacks that its SOC observed to help defenders analyze if they’ve been affected and need to take conduct mitigations.
