Blog
/
OT
/
May 11, 2023

Securing OT Systems: The Limits of the Air Gap Approach

Air-gapped security measures are not enough for resilience against cyber attacks. Read about how to gain visibility & reduce your cyber vulnerabilities.
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
Max Lesser
Head of U.S. Policy Analysis and Engagement
Default blog imageDefault blog imageDefault blog imageDefault blog imageDefault blog imageDefault blog image
11
May 2023

At a Glance:

  • Air gaps reduce cyber risk, but they do not prevent modern cyber attacks
  • Having visibility into an air-gapped network is better than assuming your defenses are impenetrable and having zero visibility
  • Darktrace can provide visibility and resiliency without jeopardizing the integrity of the air gap

What is an 'Air Gap'?

Information technology (IT) needs to fluidly connect with the outside world in order channel a flow of digital information across everything from endpoints and email systems to cloud and hybrid infrastructures. At the same time, this high level of connectivity makes IT systems particularly vulnerable to cyber-attacks.  

Operational technology (OT), which controls the operations of physical processes, are considerably more sensitive. OT often relies on a high degree of regularity to maintain continuity of operations. Even the slightest disturbance can lead to disastrous results. Just a few seconds of delay on a programmable logic controller (PLC), for example, can significantly disrupt a manufacturing assembly line, leading to downtime at a considerable cost. In worst-case scenarios, disruptions to OT can even threaten human safety. 

An air gap is a ‘digital moat’ where data cannot enter or leave OT environments unless it is transferred manually.

Organizations with OT have traditionally tried to reconcile this conflict between IT and OT by attempting to separate them completely. Essentially, the idea is to let IT do what IT does best — facilitate activities like communication and data transfer at rapid speeds, thus allowing people to connect with each other and access information and applications in an efficient capacity. But at the same time, erect an air gap between IT and OT so that any cyber threats that slip into IT systems do not then spread laterally into highly sensitive, mission-critical OT systems. This air gap is essentially a ‘digital moat’ where data cannot enter or leave OT environments unless it is transferred manually.

Limitations of the Air Gap

The air gap approach makes sense, but it is far from perfect. First, many organizations that believe they have completely air-gapped systems in fact have unknown points of IT/OT convergence, that is, connections between IT and OT networks of which they are unaware. 

Many organizations today are also intentionally embracing IT/OT convergence to reap the benefits of digital transformation of their OT, in what is often called Industry 4.0. Examples include the industrial cloud (or ICSaaS), the industrial internet of things (IIoT), and other types of cyber-physical systems that offer increased efficiency and expanded capabilities when compared to more traditional forms of OT. Organizations may also embrace IT/OT convergence due to a lack of human capital, as convergence can make processes simpler and more efficient.

Even when an organization does have a true air gap (which is nearly impossible to confirm without full visibility across IT and OT environments), the fact is that there are a variety of ways for attackers to ‘jump the air gap'. Full visibility across IT and OT ecosystems in a single pane of glass is thus essential for organizations seeking to secure their OT. This is not only to illuminate any points of IT/OT convergence and validate the fact that an air gap exists in the first place, but also to see when an attack slips through the air gap.

Figure 1: Darktrace/OT's unified view of IT and OT environments.

Air Gap Attack Vectors

Even a perfect air gap will be vulnerable to a variety of different attack vectors, including (but not limited to) the following: 

  • Physical compromise: An adversary bypasses physical security and gains access directly to the air-gapped network devices. Physical access is by far the most effective and obvious technique.
  • Insider threats: Someone who is part of an organization and has access to air-gapped secure systems intentionally or unintentionally compromises a system.
  • Supply chain compromise: A vendor with legitimate access to air-gapped systems unwittingly is compromised and brings infected devices into a network. 
  • Misconfiguration: Misconfiguration of access controls or permissions allows an attacker to access the air-gapped system through a separate device on the network.
  • Social engineering (media drop): If an attacker was able to successfully conduct a malicious USB/media drop and an employee was to use that media within the air-gapped system, the network could be compromised. 
  • Other advanced tactics: Thermal manipulation, covert surface vibrations, LEDs, ultrasonic transmissions, radio signals, and magnetic fields are among a range of advanced tactics documented and demonstrated by researchers at Ben Gurion University. 

Vulnerabilities of Air-Gapped Systems

Aside from susceptibility to advanced techniques, tactics, and procedures (TTPs) such as thermal manipulation and magnetic fields, more common vulnerabilities associated with air-gapped environments include factors such as unpatched systems going unnoticed, lack of visibility into network traffic, potentially malicious devices coming on the network undetected, and removable media being physically connected within the network. 

Once the attack is inside OT systems, the consequences can be disastrous regardless of whether there is an air gap or not. However, it is worth considering how the existence of the air gap can affect the time-to-triage and remediation in the case of an incident. For example, the existence of an air gap may seriously limit an incident response vendor’s ability to access the network for digital forensics and response. 

Kremlin Hackers Jumping the Air Gap 

In 2018, the U.S. Department of Homeland Security (DHS) issued an alert documenting the TTPs used by Russian threat actors known as Dragonfly and Energetic Bear. Further reporting alleged that these groups ‘jumped the air gap,’ and, concerningly, gained the ability to disable the grid at the time of their choosing. 

These attackers successfully gained access to sensitive air-gapped systems across the energy sector and other critical infrastructure sectors by targeting vendors and suppliers through spear-phishing emails and watering hole attacks. These vendors had legitimate access to air-gapped systems, and essentially brought the infection into these systems unintentionally when providing support services such as patch deployment.

This incident reveals that even if a sensitive OT system has complete digital isolation, this robust air gap still cannot fully eliminate one of the greatest vulnerabilities of any system—human error. Human error would still hold if an organization went to the extreme of building a faraday cage to eliminate electromagnetic radiation. Air-gapped systems are still vulnerable to social engineering, which exploits human vulnerabilities, as seen in the tactics that Dragonfly and Energetic Bear used to trick suppliers, who then walked the infection right through the front door. 

Ideally, a technology would be able to identify an attack regardless of whether it is caused by a compromised supplier, radio signal, or electromagnetic emission. By spotting subtle deviations from a device, human, or network’s normal ‘pattern of life’, Self-Learning AI detects even the most nuanced forms of threatening behavior as they emerge — regardless of the source or cause of the threat.

Darktrace/OT for Air-Gapped Environments

Darktrace/OT for air-gapped environments is a physical appliance that deploys directly to the air-gapped system. Using raw digital data from an OT network to understand the normal pattern of life, Darktrace/OT does not need any data or threat feeds from external sources because the AI builds an innate understanding of self without third-party support. 

Because all data-processing and analytics are performed locally on the Darktrace appliance, there is no requirement for Darktrace to have a connection out to the internet. As a result, Darktrace/OT provides visibility and threat detection to air-gapped or highly segmented networks without jeopardizing their integrity. If a human or machine displays even the most nuanced forms of threatening behavior, the solution can illuminate this in real time. 

Security professionals can then securely access Darktrace alerts from anywhere within the network, using a web browser and encrypted HTTPS, and in line with your organization’s network policies.

Figure 2: Darktrace/OT detecting anomalous connections to a SCADA ICS workstation.

With this deployment, Darktrace offers all the critical insights demonstrated in other Darktrace/OT deployments, including (but not limited to) the following:

Organizations seeking to validate whether they have an air gap in the first place and maintain the air gap as their IT and OT environments evolve will greatly benefit from the comprehensive visibility and continuous situational awareness offered by Darktrace’s Self-Learning AI. Also, organizations looking to poke holes in their air gap to embrace the benefits of IT/OT convergence will find that Self-Learning AI’s vigilance spots cyber-attacks that slip through. 

Whatever your organizations goals—be it embracing IIoT or creating a full-blown DMZ—by learning ‘you’, Darktrace’s Self-Learning AI can help you achieve them safely and securely. 

Learn more about Darktrace/OT

Credit to: Daniel Simonds and Oakley Cox for their contribution to this blog.

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
Max Lesser
Head of U.S. Policy Analysis and Engagement

More in this series

No items found.

Blog

/

Network

/

April 21, 2026

How a Compromised eScan Update Enabled Multi‑Stage Malware and Blockchain C2

multi-stage malwareDefault blog imageDefault blog image

The rise of supply chain attacks

In recent years, the abuse of trusted software has become increasingly common, with supply chain compromises emerging as one of the fastest growing vectors for cyber intrusions. As highlighted in Darktrace’s Annual Threat Report 2026, attackers and state-actors continue to find significant value in gaining access to networks through compromised trusted links, third-party tools, or legitimate software. In January 2026, a supply chain compromise affecting MicroWorld Technologies’ eScan antivirus product was reported, with malicious updates distributed to customers through the legitimate update infrastructure. This, in turn, resulted in a multi‑stage loader malware being deployed on compromised devices [1][2].

An overview of eScan exploitation

According to eScan’s official threat advisory, unauthorized access to a regional update server resulted in an “incorrect file placed in the update distribution path” [3]. Customers associated with the affected update servers who downloaded the update during a two-hour window on January 20 were impacted, with affected Windows devices subsequently have experiencing various errors related to update functions and notifications [3].

While eScan did not specify which regional update servers were affected by the malicious update, all impacted Darktrace customer environments were located in the Europe, Middle East, and Africa (EMEA) region.

External research reported that a malicious 32-bit executable file , “Reload.exe”, was first installed on affected devices, which then dropped the 64-bit downloader, “CONSCTLX.exe”. This downloader establishes persistence by creating scheduled tasks such as “CorelDefrag”, which are responsible for executing PowerShell scripts. Subsequently, it evades detection by tampering with the Windows HOSTS file and eScan registry to prevent future remote updates intended for remediation. Additional payloads are then downloaded from its command-and-control (C2) server [1].

Darktrace’s coverage of eScan exploitation

Initial Access and Blockchain as multi-distributed C2 Infrastructure

On January 20, the same day as the aforementioned two‑hour exploit window, Darktrace observed multiple devices across affected networks downloading .dlz package files from eScan update servers, followed by connections to an anomalous endpoint, vhs.delrosal[.]net, which belongs to the attackers’ C2 infrastructure.

The endpoint contained a self‑signed SSL certificate with the string “O=Internet Widgits Pty Ltd, ST=SomeState, C=AU”, a default placeholder commonly used in SSL/TLS certificates for testing and development environments, as well as in malicious C2 infrastructure [4].

Utilizing a multi‑distributed C2 infrastructure, the attackers also leveraged domains linked with the Solana open‑source blockchain for C2 purposes, namely “.sol”. These domains were human‑readable names that act as aliases for cryptocurrency wallet addresses. As browsers do not natively resolve .sol domains, the Solana Naming System (formerly known as Bonfida, an independent contributor within the Solana ecosystem) provides a proxy service, through endpoints such as sol-domain[.]org, to enable browser access.

Darktrace observed devices connecting to blackice.sol-domain[.]org, indicating that attackers were likely using this proxy to reach a .sol domain for C2 activity. Given this behavior, it is likely that the attackers leveraged .sol domains as a dead drop resolver, a C2 technique in which threat actors host information on a public and legitimate service, such as a blockchain. Additional proxy resolver endpoints, such as sns-resolver.bonfida.workers[.]dev, were also observed.

Solana transactions are transparent, allowing all activity to be viewed publicly. When Darktrace analysts examined the transactions associated with blackice[.]sol, they observed that the earliest records dated November 7, 2025, which coincides with the creation date of the known C2 endpoint vhs[.]delrosal[.]net as shown in WHOIS Lookup information [4][5].

WHOIS Look records of the C2 endpoint vhs[.]delrosal[.]net.
Figure 1: WHOIS Look records of the C2 endpoint vhs[.]delrosal[.]net.
 Earliest observed transaction record for blackice[.]sol on public ledgers.
Figure 2: Earliest observed transaction record for blackice[.]sol on public ledgers.

Subsequent instructions found within the transactions contained strings such as “CNAME= vhs[.]delrosal[.]net”, indicating attempts to direct the device toward the malicious endpoint. A more recent transaction recorded on January 28 included strings such as “hxxps://96.9.125[.]243/i;code=302”, suggesting an effort to change C2 endpoints. Darktrace observed multiple alerts triggered for these endpoints across affected devices.

Similar blockchain‑related endpoints, such as “tumama.hns[.]to”, were also observed in C2 activities. The hns[.]to service allows web browsers to access websites registered on Handshake, a decentralized blockchain‑based framework designed to replace centralized authorities and domain registries for top‑level domains. This shift toward decentralized, blockchain‑based infrastructure likely reflects increased efforts by attackers to evade detection.

In outgoing connections to these malicious endpoints across affected networks, Darktrace / NETWORK recognized that the activity was 100% rare and anomalous for both the devices and the wider networks, likely indicative of malicious beaconing, regardless of the underlying trusted infrastructure. In addition to generating multiple model alerts to capture this malicious activity across affected networks, Darktrace’s Cyber AI Analyst was able to compile these separate events into broader incidents that summarized the entire attack chain, allowing customers’ security teams to investigate and remediate more efficiently. Moreover, in customer environments where Darktrace’s Autonomous Response capability was enabled, Darktrace took swift action to contain the attack by blocking beaconing connections to the malicious endpoints, even when those endpoints were associated with seemingly trustworthy services.

Conclusion

Attacks targeting trusted relationships continue to be a popular strategy among threat actors. Activities linked to trusted or widely deployed software are often unintentionally whitelisted by existing security solutions and gateways. Darktrace observed multiple devices becoming impacted within a very short period, likely because tools such as antivirus software are typically mass‑deployed across numerous endpoints. As a result, a single compromised delivery mechanism can greatly expand the attack surface.

Attackers are also becoming increasingly creative in developing resilient C2 infrastructure and exploiting legitimate services to evade detection. Defenders are therefore encouraged to closely monitor anomalous connections and file downloads. Darktrace’s ability to detect unusual activity amidst ever‑changing tactics and indicators of compromise (IoCs) helps organizations maintain a proactive and resilient defense posture against emerging threats.

Credit to Joanna Ng (Associate Principal Cybersecurity Analyst) and Min Kim (Associate Principal Cybersecurity Analyst) and Tara Gould (Malware Researcher Lead)

Edited by Ryan Traill (Content Manager)

Appendices

Darktrace Model Detections

  • Anomalous File::Zip or Gzip from Rare External Location
  • Anomalous Connection / Suspicious Self-Signed SSL
  • Anomalous Connection / Rare External SSL Self-Signed
  • Anomalous Connection / Suspicious Expired SSL
  • Anomalous Server Activity / Anomalous External Activity from Critical Network Device

List of Indicators of Compromise (IoCs)

  • vhs[.]delrosal[.]net – C2 server
  • tumama[.]hns[.]to – C2 server
  • blackice.sol-domain[.]org – C2 server
  • 96.9.125[.]243 – C2 Server

MITRE ATT&CK Mapping

  • T1071.001 - Command and Control: Web Protocols
  • T1588.001 - Resource Development
  • T1102.001 - Web Service: Dead Drop Resolver
  • T1195 – Supple Chain Compromise

References

[1] https://www.morphisec.com/blog/critical-escan-threat-bulletin/

[2] https://www.bleepingcomputer.com/news/security/escan-confirms-update-server-breached-to-push-malicious-update/

[3] hxxps://download1.mwti.net/documents/Advisory/eScan_Security_Advisory_2026[.]pdf

[4] https://www.virustotal.com/gui/domain/delrosal.net

[5] hxxps://explorer.solana[.]com/address/2wFAbYHNw4ewBHBJzmDgDhCXYoFjJnpbdmeWjZvevaVv

Continue reading
About the author
Joanna Ng
Associate Principal Analyst

Blog

/

/

April 17, 2026

Why Behavioral AI Is the Answer to Mythos

mythos behavioral aiDefault blog imageDefault blog image

How AI is breaking the patch-and-prevent security model

The business world was upended last week by the news that Anthropic has developed a powerful new AI model, Claude Mythos, which poses unprecedented risk because of its ability to expose flaws in IT systems.  

Whether it’s Mythos or OpenAI’s GPT-5.4-Cyber, which was just announced on Tuesday, supercharged AI models in the hands of hackers will allow them to carry out attacks at machine speed, much faster than most businesses can stop them.  

This news underscores a stark reality for all leaders: Patching holes alone is not a sufficient control against modern cyberattacks. You must assume that your software is already vulnerable right now. And while LLMs are very good at spotting vulnerabilities, they’re pretty bad at reliably patching them.

Project Glasswing members say it could take months or years for patches to be applied. While that work is done, enterprises must be protected against Zero-Day attacks, or security holes that are still undiscovered.  

Most cybersecurity strategies today are built like a daily multivitamin: broad, preventative, and designed to keep the system generally healthy over time. Patch regularly. Update software. Reduce known vulnerabilities. It’s necessary, disciplined, and foundational. But it’s also built for a world where the risks are well known and defined, cycles are predictable, and exposure unfolds at a manageable pace.

What happens when that model no longer holds?

The AI cyber advantage: Behavioral AI

The vulnerabilities exposed by AI systems like Mythos aren’t the well-understood risks your “multivitamin” was designed to address. They are transient, fast-emerging entry points that exist just long enough to be exploited.

In that environment, prevention alone isn’t enough. You don’t need more vitamins—you need a painkiller. The future of cybersecurity won’t be defined by how well you maintain baseline health. It will be defined by how quickly you respond when something breaks and every second counts.

That’s why behavioral AI gives businesses a durable cyber advantage. Rather than trying to figure out what the attacker looks like, it learns what “normal” looks like across the digital ecosystem of each individual business.  

That’s exactly how behavioral AI works. It understands the self, or what's normal for the organization, and then it can spot deviations in from normal that are actually early-stage attacks.

The Darktrace approach to cybersecurity

At Darktrace, we’ve been defending our 10,000 customers using behavioral AI cybersecurity developed in our AI Research Centre in Cambridge, U.K.

Darktrace was built on the understanding that attacks do not arrive neatly labeled, and that the most damaging threats often emerge before signatures, indicators, or public disclosures can catch up.  

Our AI algorithms learn in real time from your personalized business data to learn what’s normal for every person and every asset, and the flows of data within your organization. By continuously understanding “normal” across your entire digital ecosystem, Darktrace identifies and contains threats emerging from unknown vulnerabilities and compromised supply chain dependencies, autonomously curtailing attacks at machine speed.  

Security for novel threats

Darktrace is built for a world where AI is not just accelerating attacks, but fundamentally reshaping how they originate. What makes our AI so unique is that it's proven time and again to identify cyber threats before public vulnerability disclosures, such as critical Ivanti vulnerabilities in 2025 and SAP NetWeaver exploitations tied to nation-state threat actors.  

As AI reshapes how vulnerabilities are found and exploited, cybersecurity must be anchored in something more durable than a list of known flaws. It requires a real-time understanding of the business itself: what belongs, what does not, and what must be stopped immediately.

What leaders should do right now

The leadership priority must shift accordingly.

First, stop treating unknown vulnerabilities as an edge case. AI‑driven discovery makes them the norm. Security programs built primarily around known flaws, signatures, and threat intelligence will always lag behind an attacker that is operating in real time.

Second, insist on an understanding of what is actually normal across the business. When threats are novel, labels are useless. The earliest and most reliable signal of danger is abnormal behavior—systems, users, or data flows that suddenly depart from what is expected. If you cannot see that deviation as it happens, you are effectively blind during the most critical window.

Finally, assume that the next serious incident will occur before remediation guidance is available. Ask what happens in those first minutes and hours. The organizations that maintain resilience are not the ones waiting for disclosure cycles to catch up—they are the ones that can autonomously identify and contain emerging threats as they unfold.

This is the reality of cybersecurity in an AI‑shaped world. Patching and prevention remain important foundations, but the advantage now belongs to those who can respond instantly when the unpredictable occurs.

Behavioral AI is security designed not just for known threats, but for the ones that AI will discover next.

[related-resource]

Continue reading
About the author
Ed Jennings
President and CEO
Your data. Our AI.
Elevate your network security with Darktrace AI