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July 7, 2021

How Cyber-Attacks Take Down Critical Infrastructure

Cyber-attacks can bypass IT/OT security barriers and threaten your organization's infrastructure. Here's how you can stay protected in today's threat landscape.
Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Oakley Cox
Director of Product
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07
Jul 2021

Balancing Operational Continuity and Safety in Critical Infrastructure

The recent high-profile attacks against Colonial Pipeline and JBS Foods highlight that operational technology (OT) — the devices that drive gas flows and food processing, along with essentially all other machine-driven physical processes — does not need to be directly targeted in order to be shut down as the result of a cyber-attack.

Indeed, in the Colonial Pipeline incident, the information technology (IT) systems were reportedly compromised, with operations shut down intentionally out of an abundance of caution, that is, so as to not risk the attack spreading to OT and threatening safety. This highlights that threats to both human and environmental safety, along with uncertainty as to the scope of infection, present risk factors for these sensitive industrial environments.

Continuity through availability and integrity

In most countries, critical infrastructure (CI) — ranging from power grids and pipelines to transportation and health care — must maintain continuous activity. The recent ransomware attack against Colonial Pipeline demonstrates why this is the case, where gas shortages due to the compromise led to dangerous panic buys and long lines at the pumps.

Ensuring continuous operation of critical infrastructure requires safeguarding the availability and integrity of machinery. This means that organizations overseeing critical infrastructure must foresee any possible risks and implement systems, procedures, and technologies that mitigate or remove these risks so as to keep their operations running.

Operational demand versus safety

Alongside this requirement for operational continuity, and often in opposition to it, is the requirement for operational safety. These requirements can be in opposition because operational continuity demands that devices remain up and running at all costs, and operational safety demands that humans and the environment be protected at all costs.

Safety measures in critical infrastructure have improved and become increasingly prioritized over the last 50 years following numerous high-profile incidents, such as the Bhopal chemical disaster, the Texas City refinery explosion, and the Deepwater Horizon oil spill. Appropriate safety precautions could have likely prevented these incidents, but at the expense of operational continuity.

Consequently, administrators of critical infrastructure have to balance the very real threat that an incident may pose to both human life and the environment with the demand to remain operational at all times. More often than not, the final decision regarding what constitutes an acceptable risk is determined by budgets and cost-benefit analyses.

Cyber-attack: A rising risk profile for critical infrastructure

In 2010, the discovery of the Stuxnet malware — which resulted in a nuclear facility in Iran having its centrifuges ruined via compromised programmable logic controllers (PLCs) — demonstrated that critical infrastructure could be targeted by a cyber-attack.

At the time of Stuxnet, critical infrastructure industries used computers designed to ensure operational continuity with little regard for cyber security, as at the time the risk of a cyber-attack seemed either non-existent or vanishingly low. Since then, a number of attacks targeting industrial environments that have emerged on the global threat landscape.

Figure 1: An overview of distinctive methods used in attacks against industrial environments

Classic strains of industrial malware, such as Stuxnet, Triton, and Industroyer, have historically been installed via removable media, such as USB. This is because OT networks are traditionally segregated from the Internet in what is known as an ‘air gap.’ And this remains a prevalent vector of attack, with a study recently finding that cyber-threats installed via USB and other external media doubled in 2021, with 79% of these holding the potential to disrupt OT.

In many ways, operational demands in the subsequent 10 years have made critical infrastructure even more vulnerable. These include the convergence of information technology and operational technology (IT/OT convergence), the adoption of devices in the Industrial Internet of Things (IIoT), and the deprecation of manual back-up systems. This means that OT can be disrupted by cyber-attacks that first target IT systems, rather than having to be installed manually via external media.

At the same time, recent government initiatives — such as the Department of Energy’s 100-day ‘cyber sprint’ to protect electricity operations and President Biden’s Executive Order on Improving the Nation’s Cybersecurity — and regulatory frameworks and directives such as the EU’s NIS directive have either encouraged or mandated that critical infrastructure industries start addressing this new risk.

With the severe and persistent threat that cyber-attacks pose to critical infrastructure, including maritime cybersecurity, and the increasing calls to address the issue, the question remains as to how to best achieve robust cyber defense.

Assessing the risk

To claim administrators of critical infrastructure are ignorant or oblivious to the threat posed by cyber-attacks would be unfair. Many organizations have implemented changes to mitigate or remove the risk either as a result of regulation or their own forward thinking.

However, these projects can take years, even decades. High costs and ever-changing operational demand also mean that these projects may never fully remove the risk.

As a result, many operators may understand the threat of a cyber-attack but not be in a position to do anything about it in the short or medium term. Instead, procedures have to be put in place to minimize risk even if this threatens operational continuity.

For example, a risk assessment may decide it is best to shut down all OT operations in the event of a cyber-attack in order to avoid a major accident. This abundance of caution is forced upon operators, who do not have the ability to immediately confirm the boundaries of a compromise. The prevalence of cyber insurance provides this option with further appeal. Any losses incurred by stopping operations can theoretically be recouped and the risk is therefore transferred.

While the full details of the Colonial Pipeline ransomware incident are still to be determined, the sequence of events outlined below provides a plausible explanation for how a cyber-attack could take down critical infrastructure, even when that cyber-attack does not reach or even target OT systems. Indeed, the CEO of Colonial Pipeline, in a testimony to congress, confirmed “the imperative to isolate and contain the attack to help ensure the malware did not spread to the operational technology network, which controls our pipeline operations, if it had not already.”

Figure 2: A sequence of events which may lead to critical infrastructure being shut down by a cyber-attack, even when that cyber-attack doesn’t directly impact OT networks

The limits of securing IT or OT in isolation

The emergence of OT cyber security solutions in the last five years demonstrates that critical infrastructure industries are trying to find a way to address the risks posed by cyber-attacks. But these solutions have limited scope, as they assume IT and OT are separated and use legacy security techniques such as malware signatures and patch management.

The 2021 SANS ICS Security Summit highlighted how the OT security community suffers from a lack of visibility in knowing and understanding their networks. For many organizations, simply determining whether an unusual incident is an attack or the result of a software error is a challenge.

Given that most OT cyber-attacks actually start in IT networks before pivoting into OT, investing in an IT security solution rather than an OT-specific solution may at first seem like a better business decision. But IT solutions fall short if an attacker successfully pivots into the OT network, or if the attacker is a rogue insider who already has direct access to the OT network. A siloed approach to securing either IT or OT in isolation will thus fall short of the full scope needed to safeguard industrial systems.

It is clear that a mature security posture for critical infrastructure would include security solutions for both IT and OT. Even then, using separate solutions to protect the IT and OT networks is limited, as it presents challenges when defending network boundaries and detecting incidents when an attacker pivots from IT to OT. Under time pressure, a security team does not want changes in visibility, detection, language or interface while trying to determine whether a threat crossed the ‘boundary’ between IT and OT.

Separate solutions can also make detecting an attacker abusing traditional IT attack TTPs within an OT network much harder if the security team is relying on a purely OT solution to defend the OT environment. Examples of this include the abuse of IT remote management tools to affect industrial environments, such as in the suspected cyber-attack at the Florida water facility earlier this year. Cybersecurity for utilities is becoming increasingly important as these sectors face growing cyber threats that can disrupt essential services.

Using AI to minimize cyber risk and maximize cyber safety

In contrast, Darktrace AI is able to defend an entire cyber ecosystem estate, building a ‘pattern of life’ across IT and OT, as well as the points at which they converge. Consequently, cyber security teams can use a single pane of glass to detect and respond to cyber-attacks as they emerge and develop, regardless of where they are in the environment.

Use cases for Darktrace’s Self-Learning AI include containing pre-existing threats to maintain continuous operations. This was seen when Darktrace’s AI detected pre-existing infections and acted autonomously to contain the threat, allowing the operator to leave infected IIoT devices active while waiting for replacements. Darktrace can also thwart ransomware in IT before it can spread into OT, as when Darktrace detected a ransomware attack targeting a supplier for critical infrastructure in North America at its earliest stages.

Darktrace’s unified protection, including visibility and early detection of zero-days, empowers security teams to overcome uncertainty and make a confident decision not to shut down operations. Darktrace has already demonstrated this ability in the wild, and allows organizations to understand normal machine and human behavior in order to enforce this behavior, even in the face of an emerging cyber-attack.

Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Oakley Cox
Director of Product

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January 9, 2026

Maduro Arrest Used as a Lure to Deliver Backdoor

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Introduction

Threat actors frequently exploit ongoing world events to trick users into opening and executing malicious files. Darktrace security researchers recently identified a threat group using reports around the arrest of Venezuelan President Nicolàs Maduro on January 3, 2025, as a lure to deliver backdoor malware.

Technical Analysis

While the exact initial access method is unknown, it is likely that a spear-phishing email was sent to victims, containing a zip archive titled “US now deciding what’s next for Venezuela.zip”. This file included an executable named “Maduro to be taken to New York.exe” and a dynamic-link library (DLL), “kugou.dll”.  

The binary “Maduro to be taken to New York.exe” is a legitimate binary (albeit with an expired signature) related to KuGou, a Chinese streaming platform. Its function is to load the DLL “kugou.dll” via DLL search order. In this instance, the expected DLL has been replaced with a malicious one with the same name to load it.  

DLL called with LoadLibraryW.
Figure 1: DLL called with LoadLibraryW.

Once the DLL is executed, a directory is created C:\ProgramData\Technology360NB with the DLL copied into the directory along with the executable, renamed as “DataTechnology.exe”. A registry key is created for persistence in “HKCU\Software\Microsoft\Windows\CurrentVersion\Run\Lite360” to run DataTechnology.exe --DATA on log on.

 Registry key added for persistence.
Figure 2. Registry key added for persistence.
Folder “Technology360NB” created.
Figure 3: Folder “Technology360NB” created.

During execution, a dialog box appears with the caption “Please restart your computer and try again, or contact the original author.”

Message box prompting user to restart.
Figure 4. Message box prompting user to restart.

Prompting the user to restart triggers the malware to run from the registry key with the command --DATA, and if the user doesn't, a forced restart is triggered. Once the system is reset, the malware begins periodic TLS connections to the command-and-control (C2) server 172.81.60[.]97 on port 443. While the encrypted traffic prevents direct inspection of commands or data, the regular beaconing and response traffic strongly imply that the malware has the ability to poll a remote server for instructions, configuration, or tasking.

Conclusion

Threat groups have long used geopolitical issues and other high-profile events to make malicious content appear more credible or urgent. Since the onset of the war in Ukraine, organizations have been repeatedly targeted with spear-phishing emails using subject lines related to the ongoing conflict, including references to prisoners of war [1]. Similarly, the Chinese threat group Mustang Panda frequently uses this tactic to deploy backdoors, using lures related to the Ukrainian war, conventions on Tibet [2], the South China Sea [3], and Taiwan [4].  

The activity described in this blog shares similarities with previous Mustang Panda campaigns, including the use of a current-events archive, a directory created in ProgramData with a legitimate executable used to load a malicious DLL and run registry keys used for persistence. While there is an overlap of tactics, techniques and procedures (TTPs), there is insufficient information available to confidently attribute this activity to a specific threat group. Users should remain vigilant, especially when opening email attachments.

Credit to Tara Gould (Malware Research Lead)
Edited by Ryan Traill (Analyst Content Lead)

Indicators of Compromise (IoCs)

172.81.60[.]97
8f81ce8ca6cdbc7d7eb10f4da5f470c6 - US now deciding what's next for Venezuela.zip
722bcd4b14aac3395f8a073050b9a578 - Maduro to be taken to New York.exe
aea6f6edbbbb0ab0f22568dcb503d731  - kugou.dll

References

[1] https://cert.gov.ua/article/6280422  

[2] https://www.ibm.com/think/x-force/hive0154-mustang-panda-shifts-focus-tibetan-community-deploy-pubload-backdoor

[3] https://www.ibm.com/think/x-force/hive0154-targeting-us-philippines-pakistan-taiwan

[4] https://www.ibm.com/think/x-force/hive0154-targeting-us-philippines-pakistan-taiwan

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About the author
Tara Gould
Malware Research Lead

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January 9, 2026

Under Medusa’s Gaze: How Darktrace Uncovers RMM Abuse in Ransomware Campaigns

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What is Medusa Ransomware in 2025?

In 2025, the Medusa Ransomware-as-a-Service (RaaS) emerged as one of the top 10 most active ransomware threat actors [1]. Its growing impact prompted a joint advisory from the US Cybersecurity and Infrastructure Security Agency (CISA) and the Federal Bureau of Investigation (FBI) [3]. As of January 2026, more than 500 organizations have fallen victim to Medusa ransomware [2].

Darktrace previously investigated Medusa in a 2024 blog, but the group’s rapid expansion and new intelligence released in late 2025 has lead Darktrace’s Threat Research team to  investigate further. Recent findings include Microsoft’s research on Medusa actors exploiting a vulnerability in Fortra’s GoAnywhere MFT License Servlet (CVE-2025-10035)[4] and Zencec’s report on Medusa’s abuse of flaws in SimpleHelp’s remote support software (CVE-2024-57726, CVE-2024-57727, CVE-2024-57728) [5].

Reports vary on when Medusa first appeared in the wild. Some sources mention June 2021 as the earliest sightings, while others point to late 2022, when its developers transitioned to the RaaS model, as the true beginning of its operation [3][11].

Madusa Ransomware history and background

The group behind Medusa is known by several aliases, including Storm-1175 and Spearwing [4] [7]. Like its mythological namesake, Medusa has many “heads,” collaborating with initial access brokers (IABs) and, according to some evidence, affiliating with Big Game Hunting (BGH) groups such as Frozen Spider, as well as the cybercriminal group UNC7885 [3][6][13].

Use of Cyrillic in its scripts, activity on Russian-language cybercrime forums, slang unique to Russian criminal subcultures, and avoidance of targets in Commonwealth of Independent States (CIS) countries suggest that Medusa operates from Russia or an allied state [11][12].

Medusa ransomware should not be confused with other similarly named malware, such as the Medusa Android Banking Trojan, the Medusa Botnet/Medusa Stealer, or MedusaLocker ransomware. It is easily distinguishable from these variants because it appends the extension .MEDUSA to encrypted files and drops the ransom note !!!READ_ME_MEDUSA!!!.txt on compromised systems [8].

Who does Madusa Ransomware target?

The group appears to show little restraint, indiscriminately attacking organizations across all sectors, including healthcare, and is known to employ triple extortion tactics whereby sensitive data is encrypted, victims are threatened with data leaks, and additional pressure is applied through DDoS attacks or contacting the victim’s customers, rather than the more common double extortion model [13].

Madusa Ransomware TTPs

To attain initial access, Medusa actors typically purchase access to already compromised devices or accounts via IABs that employ phishing, credential stuffing, or brute-force attacks, and also target vulnerable or misconfigured Internet-facing systems.

In addition to the GoAnywhere MFT and SimpleHelp RMM flaws, other vulnerabilities exploited in Medusa attacks include ConnectWise ScreenConnect RMM (CVE-2024-1709), Microsoft Exchange Server (CVE-2021-34473, also known as ProxyShell), and Fortinet Enterprise Management Servers (CVE-2023-48788) [18][19][20][21][24][25].

Darktrace’s Coverage of Medusa Ransomware

Between December 2023 and November 2025, Darktrace observed multiple cases of file encryption related to Medusa ransomware across its customer base. When enabled, Darktrace’s Autonomous Response capability intervened early in the attack chain, blocking malicious activity before file encryption could begin.

Some of the affected were based in Europe, the Middle East and Africa (EMEA), others in the Americas (AMS), and the remainder in the Asia-Pacific and Japan region. The most impacted sectors were financial services and the automotive industry, followed by healthcare, and finally organizations in arts, entertainment and recreation, ICT, and manufacturing.

Remote Monitoring and Management (RMM) tool abuse

In most customer environments where Medusa file encryption attempts were observed, and in one case where the compromise was contained before encryption, unusual external HTTP connections associated with JWrapper were also detected. JWrapper is a legitimate tool designed to simplify the packaging, distribution, and management of Java applications, enabling the creation of executables that run across different operating systems. Many of the destination IP addresses involved in this activity were linked to SimpleHelp servers or associated with Atera.

Medusa actors appear to favor RMM tools such as SimpleHelp. Unpatched or misconfigured SimpleHelp RMM servers can serve as an initial access vector to the victims’ infrastructure.  After gaining access to SimpleHelp management servers, the threat actors edit server configuration files to redirect existing SimpleHelp RMM agents to communicate with unauthorized servers under their control.

The SimpleHelp tool is not only used for command-and-control (C2) and enabling persistence but is also observed during lateral movement within the network, downloading additional attack tools, data exfiltration, and even ransomware binary execution. Other legitimate remote access tools abused by Medusa in a similar manner to evade detection include Atera, AnyDesk, ScreenConnect, eHorus, N-able, PDQ Deploy/Inventory, Splashtop, TeamViewer, NinjaOne, Navicat, and MeshAgent [4][5][15][16][17].

Data exfiltration

Another correlation among Darktrace customers affected by Medusa was observed during the data exfiltration phase. In several environments, data was exfiltrated to the endpoints erp.ranasons[.]com or pruebas.pintacuario[.]mx (143.110.243[.]154, 144.217.181[.]205) over ports 443, 445, and 80. erp.ranasons[.]com was seemingly active between November 2024 and September 2025, while pruebas.pintacuario[.]mx was seen from November 2024 to March 2025. Evidence suggests that pruebas.pintacuario[.]mx previously hosted a SimpleHelp server [22][23].

Apart from RMM tools, Medusa is also known to use Rclone and Robocopy for data exfiltration [3][19]. During one Medusa compromise detected in mid-2024, the customer’s data was exfiltrated to external destinations associated with the Ngrok proxy service using an SSH-2.0-rclone client.

Medusa Compromise Leveraging SimpleHelp

In Q4 2025, Darktrace assisted a European company impacted by Medusa ransomware. The organization had partial Darktrace / NETWORK coverage and had configured Darktrace’s Autonomous Response capability to require manual confirmation for all actions. Despite these constraints, data received through the customer’s security integration with CrowdStrike Falcon enabled Darktrace analysts to reconstruct the attack chain, although the initial access vector remains unclear due to limited visibility.

In late September 2025, a device out of the scope of Darktrace's visibility began scanning the network and using RDP, NTLM/SMB, DCE_RPC, and PowerShell for lateral movement.

CrowdStrike “Defense Evasion: Disable or Modify Tools” alerts related to a suspicious driver (c:\windows\[0-9a-b]{4}.exe) and a PDQ Deploy executable (share=\\<device_hostname>\ADMIN$ file=AdminArsenal\PDQDeployRunner\service-1\exec\[0-9a-b]{4}.exe) suggest that the attackers used the Bring Your Own Vulnerable Driver (BYOVD) technique to terminate antivirus processes on network devices, leveraging tools such as KillAV or AbyssWorker along with the PDQ Software Deployment solution [19][26].

A few hours later, Darktrace observed the same device that had scanned the network writing Temp\[a-z]{2}.exe over SMB to another device on the same subnet. According to data from the CrowdStrike alert, this executable was linked to an RMM application located at C:\Users\<compromised_user>\Documents\[a-z]{2}.exe. The same compromised user account later triggered a CrowdStrike “Command and Control: Remote Access Tools” alert when accessing C:\ProgramData\JWrapper-Remote Access\JWrapper-Remote Access Bundle-[0-9]{11}\JWrapperTemp-[0-9]{10}-[0-9]{1}-app\bin\windowslauncher.exe [27].

An executable file associated with the SimpleHelp RMM tool being written to other devices using the SMB protocol, as detected by Darktrace.
Figure 1: An executable file associated with the SimpleHelp RMM tool being written to other devices using the SMB protocol, as detected by Darktrace.

Soon after, the destination device and multiple other network devices began establishing connections to 31.220.45[.]120 and 213.183.63[.]41, both of which hosted malicious SimpleHelp RMM servers. These C2 connections continued for more than 20 days after the initial compromise.

CrowdStrike integration alerts for the execution of robocopy . "c:\windows\\" /COPY:DT /E /XX /R:0 /W:0 /NP /XF RunFileCopy.cmd /IS /IT commands on several Windows servers, suggested that this utility was likely used to stage files in preparation for data exfiltration [19].

Around two hours later, Darktrace detected another device connecting to the attacker’s SimpleHelp RMM servers. This internal server had ‘doc’ in its hostname, indicating it was likely a file server. It was observed downloading documents from another internal server over SMB and uploading approximately 70 GiB of data to erp.ranasons[.]com (143.110.243[.]154:443).

Data uploaded to erp.ranasons[.]com and the number of model alerts from the exfiltrating device, represented by yellow and orange dots.
Figure 2: Data uploaded to erp.ranasons[.]com and the number of model alerts from the exfiltrating device, represented by yellow and orange dots.

Darktrace’s Cyber AI Analyst autonomously investigated the unusual connectivity, correlating the separate C2 and data exfiltration events into a single incident, providing greater visibility into the ongoing attack.

Cyber AI Analyst identified a file server making C2 connections to an attacker-controlled SimpleHelp server (213.183.63[.]41) and exfiltrating data to erp.ranasons[.]com.
Figure 3: Cyber AI Analyst identified a file server making C2 connections to an attacker-controlled SimpleHelp server (213.183.63[.]41) and exfiltrating data to erp.ranasons[.]com.
The same file server that connected to 213.183.63[.]41 and exfiltrated data to erp.ranasons[.]com was also observed attempting to connect to an IP address associated with Moscow, Russia (193.37.69[.]154:7070).
Figure 4: The same file server that connected to 213.183.63[.]41 and exfiltrated data to erp.ranasons[.]com was also observed attempting to connect to an IP address associated with Moscow, Russia (193.37.69[.]154:7070).

One of the devices connecting to the attacker's SimpleHelp RMM servers was also observed downloading 35 MiB from [0-9]{4}.filemail[.]com. Filemail, a legitimate file-sharing service, has reportedly been abused by Medusa actors to deliver additional malicious payloads [11].

A device controlled remotely via SimpleHelp downloading additional tooling from the Filemail file-sharing service.
Figure 5: A device controlled remotely via SimpleHelp downloading additional tooling from the Filemail file-sharing service.

Finally, integration alerts related to the ransomware binary, such as c:\windows\system32\gaze.exe and <device_hostname>\ADMIN$ file=AdminArsenal\PDQDeployRunner\service-1\exec\gaze.exe, along with “!!!READ_ME_MEDUSA!!!.txt” ransom notes were observed on network devices. This indicates that file encryption in this case was most likely carried out directly on the victim hosts rather than via the SMB protocol [3].

Conclusion

Threat actors, including nation-state actors and ransomware groups like Medusa, have long abused legitimate commercial RMM tools, typically used by system administrators for remote monitoring, software deployment, and device configuration, instead of relying on remote access trojans (RATs).

Attackers employ existing authorized RMM tools or install new remote administration software to enable persistence, lateral movement, data exfiltration, and ingress tool transfer. By mimicking legitimate administrative behavior, RMM abuse enables attackers to evade detection, as security software often implicitly trusts these tools, allowing attackers to bypass traditional security controls [28][29][30].

To mitigate such risks, organizations should promptly patch publicly exposed RMM servers and adopt anomaly-based detection solutions, like Darktrace / NETWORK, which can distinguish legitimate administrative activity from malicious behavior, applying rapid response measures through its Autonomous Response capability to stop attacks in their tracks.

Darktrace delivers comprehensive network visibility and Autonomous Response capabilities, enabling real-time detection of anomalous activity and rapid mitigation, even if an organization fall under Medusa’s gaze.

Credit to Signe Zaharka (Principal Cyber Analyst) and Emma Foulger (Global Threat Research Operations Lead

Edited by Ryan Traill (Analyst Content Lead)

Appendices

List of Indicators of Compromise (IoCs)

IoC - Type - Description + Confidence + Time Observed

185.108.129[.]62 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - March 7, 2023

185.126.238[.]119 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - November 26-27, 2024

213.183.63[.]41 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - November 28, 2024 - Sep 30, 2025

213.183.63[.]42 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - July 4 -9 , 2024

31.220.45[.]120 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - September 12 - Oct 20 , 2025

91.92.246[.]110 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - May 24, 2024

45.9.149[.]112:15330 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - June 21, 2024

89.36.161[.]12 IP address Malicious SimpleHelp server observed during Medusa attacks (High confidence) - June 26-28, 2024

193.37.69[.]154:7070 IP address Suspicious RU IP seen on a device being controlled via SimpleHelp and exfiltrating data to a Medusa related endpoint - September 30 - October 20, 2025

erp.ranasons[.]com·143.110.243[.]154 Hostname Data exfiltration destination - November 27, 2024 - September 30, 2025

pruebas.pintacuario[.]mx·144.217.181[.]205 - Hostname Data exfiltration destination - November 27, 2024  -  March 26, 2025

lirdel[.]com · 44.235.83[.]125/a.msi (1b9869a2e862f1e6a59f5d88398463d3962abe51e19a59) File & hash Atera related file downloaded with PowerShell - June 20, 2024

wizarr.manate[.]ch/108.215.180[.]161:8585/$/1dIL5 File Suspicious file observed on one of the devices exhibiting unusual activity during a Medusa compromise - February 28, 2024

!!!READ_ME_MEDUSA!!!.txt" File - Ransom note

*.MEDUSA - File extension        File extension added to encrypted files

gaze.exe – File - Ransomware binary

Darktrace Model Coverage

Darktrace / NETWORK model detections triggered during connections to attacker controlled SimpleHelp servers:

Anomalous Connection/Anomalous SSL without SNI to New External

Anomalous Connection/Multiple Connections to New External UDP Port

Anomalous Connection/New User Agent to IP Without Hostname

Anomalous Connection/Rare External SSL Self-Signed

Anomalous Connection/Suspicious Self-Signed SSL

Anomalous File/EXE from Rare External Location

Anomalous Server Activity/Anomalous External Activity from Critical Network Device

Anomalous Server Activity/New User Agent from Internet Facing System

Anomalous Server Activity/Outgoing from Server

Anomalous Server Activity/Rare External from Server

Compromise/High Volume of Connections with Beacon Score

Compromise/Large Number of Suspicious Failed Connections

Compromise/Ransomware/High Risk File and Unusual SMB

Device/New User Agent

Unusual Activity/Unusual External Data to New Endpoint

Unusual Activity/Unusual External Data Transfer

Darktrace / NETWORK Model Detections during the September/October 2025 Medusa attack:

Anomalous Connection / Data Sent to Rare Domain

Anomalous Connection / Download and Upload

Anomalous Connection / Low and Slow Exfiltration

Anomalous Connection / New User Agent to IP Without Hostname

Anomalous Connection / Uncommon 1 GiB Outbound

Anomalous Connection / Unusual Admin RDP Session

Anomalous Connection / Unusual Incoming Long Remote Desktop Session

Anomalous Connection / Unusual Long SSH Session

Anomalous File / EXE from Rare External Location

Anomalous File / Internal/Unusual Internal EXE File Transfer

Anomalous Server Activity / Anomalous External Activity from Critical Network Device

Anomalous Server Activity / Outgoing from Server

Anomalous Server Activity / Rare External from Server

Compliance / Default Credential Usage

Compliance / High Priority Compliance Model Alert

Compliance / Outgoing NTLM Request from DC

Compliance / Possible Unencrypted Password File On Server

Compliance / Remote Management Tool On Server

Compromise / Large Number of Suspicious Failed Connections

Compromise / Large Number of Suspicious Successful Connections

Compromise / Ransomware/High Risk File and Unusual SMB

Compromise / Suspicious Beaconing Behaviour

Compromise / Suspicious HTTP and Anomalous Activity

Compromise / Sustained SSL or HTTP Increase

Compromise / Sustained TCP Beaconing Activity To Rare Endpoint

Device / ICMP Address Scan

Device / Increase in New RPC Services

Device / Initial Attack Chain Activity

Device / Large Number of Model Alert

Device / Large Number of Model Alerts from Critical Network Device

Device / Lateral Movement and C2 Activity

Device / Multiple C2 Model Alert

Device / Network Scan

Device / Possible SMB/NTLM Reconnaissance

Device / Spike in LDAP Activity

Device / Suspicious Network Scan Activity

Device / Suspicious SMB Scanning Activity

Security Integration / High Severity Integration Incident

Security Integration / Low Severity Integration Incident

Unusual Activity / Enhanced Unusual External Data Transfer

Unusual Activity / Internal Data Transfer

Unusual Activity / Unusual External Activity

Unusual Activity / Unusual External Data to New Endpoint

Unusual Activity / Unusual External Data Transfer

User / New Admin Credentials on Server

Autonomous Response Actions

Antigena / Network/External Threat/Antigena File then New Outbound Block

Antigena / Network/External Threat/Antigena Ransomware Block

Antigena / Network/External Threat/Antigena Suspicious Activity Block

Antigena / Network/External Threat/Antigena Suspicious File Block

Antigena / Network/Insider Threat/Antigena Internal Anomalous File Activity

Antigena / Network/Insider Threat/Antigena Internal Data Transfer Block

Antigena / Network/Insider Threat/Antigena Large Data Volume Outbound Block

Antigena / Network/Insider Threat/Antigena Network Scan Block

Antigena / Network/Insider Threat/Antigena Unusual Privileged User Activities Block

Antigena / Network/Significant Anomaly/Antigena Alerts Over Time Block

Antigena / Network/Significant Anomaly/Antigena Controlled and Model Alert

Antigena / Network/Significant Anomaly/Antigena Enhanced Monitoring from Server Block

Antigena / Network/Significant Anomaly/Antigena Significant Server Anomaly Block

Antigena / Network/Significant Anomaly/Repeated Antigena Alerts

MITRE ATT&CK Mapping

Technique Name, Tactic, ID, Sub-Technique

Application Layer Protocol , COMMAND AND CONTROL , T1071

Automated Collection , COLLECTION , T1119

Automated Exfiltration , EXFILTRATION , T1020

Brute Force , CREDENTIAL ACCESS , T1110

Client Configurations , RECONNAISSANCE , T1592.004 , T1592

Cloud Accounts , DEFENSE EVASION ,  PERSISTENCE ,  PRIVILEGE ESCALATION ,  INITIAL ACCESS , T1078.004 , T1078

Command-Line Interface , EXECUTION ICS , T0807

Credential Stuffing , CREDENTIAL ACCESS , T1110.004 , T1110

Data Encrypted for Impact , IMPACT , T1486

Data from Network Shared Drive , COLLECTION , T1039

Data Obfuscation , COMMAND AND CONTROL , T1001

Data Staged , COLLECTION , T1074

Data Transfer Size Limits , EXFILTRATION , T1030

Default Accounts , DEFENSE EVASION ,  PERSISTENCE ,  PRIVILEGE ESCALATION ,  INITIAL ACCESS , T1078.001 , T1078

Default Credentials , LATERAL MOVEMENT ICS , T0812

Distributed Component Object Model , LATERAL MOVEMENT , T1021.003 , T1021

Drive-by Compromise , INITIAL ACCESS ICS , T0817

Drive-by Compromise , INITIAL ACCESS , T1189

Email Collection , COLLECTION , T1114

Exfiltration Over Alternative Protocol , EXFILTRATION , T1048

Exfiltration Over C2 Channel , EXFILTRATION , T1041

Exfiltration to Cloud Storage , EXFILTRATION , T1567.002 , T1567

Exploit Public-Facing Application , INITIAL ACCESS , T1190

Exploitation for Privilege Escalation , PRIVILEGE ESCALATION , T0890

Exploitation of Remote Services , LATERAL MOVEMENT , T1210

Exploits , RESOURCE DEVELOPMENT , T1588.005 , T1588

File and Directory Discovery , DISCOVERY , T1083

File Deletion , DEFENSE EVASION , T1070.004 , T1070

Graphical User Interface , EXECUTION ICS , T0823

Ingress Tool Transfer , COMMAND AND CONTROL , T1105

Lateral Tool Transfer , LATERAL MOVEMENT , T1570

LLMNR/NBT-NS Poisoning and SMB Relay , CREDENTIAL ACCESS ,  COLLECTION , T1557.001 , T1557

Malware , RESOURCE DEVELOPMENT , T1588.001 , T1588

Network Service Scanning , DISCOVERY , T1046

Network Share Discovery , DISCOVERY , T1135

Non-Application Layer Protocol , COMMAND AND CONTROL , T1095

Non-Standard Port , COMMAND AND CONTROL , T1571

One-Way Communication , COMMAND AND CONTROL , T1102.003 , T1102

Pass the Hash , DEFENSE EVASION ,  LATERAL MOVEMENT , T1550.002 , T1550

Password Cracking , CREDENTIAL ACCESS , T1110.002 , T1110

Password Guessing , CREDENTIAL ACCESS , T1110.001 , T1110

Password Spraying , CREDENTIAL ACCESS , T1110.003 , T1110

Program Download , LATERAL MOVEMENT ICS , T0843

Program Upload , COLLECTION ICS , T0845

Remote Access Software , COMMAND AND CONTROL , T1219

Remote Desktop Protocol , LATERAL MOVEMENT , T1021.001 , T1021

Remote System Discovery , DISCOVERY , T1018

Scanning IP Blocks , RECONNAISSANCE , T1595.001 , T1595

Scheduled Transfer , EXFILTRATION , T1029

Spearphishing Attachment , INITIAL ACCESS ICS , T0865

Standard Application Layer Protocol , COMMAND AND CONTROL ICS , T0869

Supply Chain Compromise , INITIAL ACCESS ICS , T0862

User Execution , EXECUTION ICS , T0863

Valid Accounts , DEFENSE EVASION ,  PERSISTENCE ,  PRIVILEGE ESCALATION ,  INITIAL ACCESS , T1078

Valid Accounts , PERSISTENCE ICS ,  LATERAL MOVEMENT ICS , T0859

Vulnerabilities , RESOURCE DEVELOPMENT , T1588.006 , T1588

Vulnerability Scanning , RECONNAISSANCE , T1595.002 , T1595

Web Protocols , COMMAND AND CONTROL , T1071.001 , T1071

References

1. https://www.intel471.com/blog/threat-hunting-case-study-medusa-ransomware

2. https://www.ransomware.live/group/medusa

3. https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-071a

4. https://www.microsoft.com/en-us/security/blog/2025/10/06/investigating-active-exploitation-of-cve-2025-10035-goanywhere-managed-file-transfer-vulnerability/

5. https://zensec.co.uk/blog/how-rmm-abuse-fuelled-medusa-dragonforce-attacks/

6. https://www.checkpoint.com/cyber-hub/threat-prevention/ransomware/medusa-ransomware-group/

7. https://cyberpress.org/medusa-ransomware-attacks-spike-42/

8. https://blog.barracuda.com/2025/02/25/medusa-ransomware-and-its-cybercrime-ecosystem

10. https://www.cyberdaily.au/security/10021-more-monster-than-myth-unpacking-the-medusa-ransomware-operation

11. https://unit42.paloaltonetworks.com/medusa-ransomware-escalation-new-leak-site/

12. https://www.bitdefender.com/en-us/blog/businessinsights/medusa-ransomware-a-growing-threat-with-a-bold-online-presence

13. https://redpiranha.net/news/medusa-ransomware-everything-you-need-know

14.  https://www.theregister.com/2025/03/13/medusa_ransomware_infects_300_critical/

15. https://www.s-rminform.com/latest-thinking/cyber-threat-advisory-medusa-and-the-simplehelp-vulnerability

16. https://nagomisecurity.com/medusa-ransomware-us-cert-alert

17. https://arcticwolf.com/resources/blog/arctic-wolf-observes-campaign-exploiting-simplehelp-rmm-software-for-initial-access/

18. https://securityboulevard.com/2025/04/medusa-ransomware-inside-the-2025-resurgence-of-one-of-the-internets-most-aggressive-threats/

19. https://thehackernews.com/2025/03/medusa-ransomware-hits-40-victims-in.html

20.  https://www.quorumcyber.com/threat-intelligence/critical-alert-medusa-ransomware-threat-highlighted-by-fbi-cisa-and-ms-isac/

21. https://brandefense.io/blog/stone-gaze-in-depth-analysis-of-medusa-ransomware/

22. https://www.darktrace.com/ja/blog/2025-cyber-threat-landscape-darktraces-mid-year-review

23. https://www.joesandbox.com/analysis/1576447/0/html

24. https://blog.barracuda.com/2025/02/25/medusa-ransomware-and-its-cybercrime-ecosystem

25. https://shassit.mit.edu/news/medusa-ransomware-attacks-on-gmail/

26. https://thehackernews.com/2025/03/medusa-ransomware-uses-malicious-driver.html

27. https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-163a

28. https://www.catonetworks.com/blog/cato-ctrl-investigation-of-rmm-tools/

29. https://redcanary.com/threat-detection-report/trends/rmm-tools/

30. https://www.proofpoint.com/us/blog/threat-insight/remote-monitoring-and-management-rmm-tooling-increasingly-attackers-first-choice

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About the author
Signe Zaharka
Principal Cyber Analyst
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