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April 10, 2023

Detecting Malicious Email Activity & AI Impersonating

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10
Apr 2023
Discover how two different phishing attempts from some known and unknown senders used a payroll diversion and credential sealing box link to harm users.

Social engineering has become widespread in the cyber threat landscape in recent years, and the near-universal use of social media today has allowed attackers to research and target victims more effectively. Social engineering involves manipulating users to carry out actions such as revealing sensitive information like login credentials or credit card details. It can also lead to user account compromises, causing huge disruption to an organization’s digital estate. 

As people use social media platforms not only for personal reasons, but also for business purposes, attackers gain information they can exploit in social engineering attacks. For example, a threat actor may attempt to impersonate a known individual or legitimate service to take advantage of a user’s established trust. This is a highly successful method of social engineering because mimicking known contacts makes it difficult for traditional security tools that rely on deny-lists to detect the attack.

In October 2022, Darktrace identified and responded to two separate malicious email campaigns in which threat actors attempted to impersonate known contacts in an effort to compromise customer devices. As it learns the normal behavior of every user in the email system, Darktrace was able to instantly detect these threats and mitigate them autonomously, preventing significant disruption to the customer networks.

Payroll Diversion Fraud Attempt Impersonating a Former Employee 

While a customer in the Canadian energy sector was trialing Darktrace in October 2022, Darktrace/Email™ identified a suspicious email seemingly sent from an employee within the organization. The email was sent to the Senior Director of Human Resources (HR) with a subject line of “Change in payroll Direct Deposit.” The email requested a change in bank account information for an employee. However, Darktrace recognized that the sender was using a free mail address that contained random letters, indicating it may have been algorithmically generated. Since this incident occurred during a trial, Darktrace/Email was not configured to take action. Otherwise, it would have prevented the email from landing in the inbox. In this case though, the email went through, bypassing all other security tools in place.

Although the email was from an unknown sender, the HR director believed the email could have been legitimate as the employee who appeared to be the sender had left the organization seven days prior and no longer had access to their corporate email account. However, after reviewing it in the Darktrace/Email dashboard, the customer grew suspicious and contacted the former employee directly to verify if the request was legitimate. The former employee validated the suspicions by confirming they had sent no such email.

Further investigation by the customer revealed that the former employee had been vocal about their departure on various social media platforms. This gave threat actors valuable information to believably impersonate the former employee and defraud the organization. 

Such attempts to target organizations’ HR departments and divert payroll are common tactics for cyber-criminals and are often identified by Darktrace/Email across the customer base. Darktrace/Email is able to instantly identify the indicators associated with these spoofing attempts and immediately bring them to the attention of the customer’s security team. 

Using Legitimate File Sharing Service to Share a Phishing Link 

On October 7, 2022, a customer in the Singaporean construction sector was targeted by a phishing campaign attempting to impersonate a law firm known to the organization. Almost 200 employees received an email with the subject line “Accepted: Valuation Agreement.” 

Figure 1: Sample of an UI view of the message held showing anomaly indicators, history, association, and validation.

Four days earlier, Darktrace observed communication between another email address associated with the law firm and an employee of the customer. Darktrace/Email noted that it was the first time this correspondent had sent emails to the customer. 

Figure 2: Metrics showing how well the sender’s domain is known within the digital environment.

The emails contained a highly unusual link to a file sharing service, (hxxps://ssvilvensstokes[.]app[.]box[.]com/notes), hidden behind the text “PREVIEW OR PRINT COPY OF DOCUMENT HERE.” Darktrace analysts investigated this event further and found that around 30 similar URLs had been identified as suspicious using OSINT security tools in October 2022, suggesting the customer was not the only target of this phishing campaign.

Figure 3: Preview of the phishing email’s body.
Figure 4: Darktrace’s evaluation of the link contained in the phishing email.

Additional OSINT work revealed that the link directed to a website which appeared to host a PDF file named “Valuation Agreement.” The recipient would then be prompted to follow another link (hulking-citrine-krypton[.]glitch[.]me), again hidden behind the text “OPEN OR ACCESS DOCUMENT HERE” to view the file. Subsequently, the user would be prompted to enter their Microsoft 365 credentials. 

Figure 5: The page displayed when the phishing link was clicked, viewed in a sandbox environment.
Figure 6: Example of a page shown when recipient clicks the second link, accessing “hulking-citrine-krypton[.]glitch[.]me”. 

This page contained the text “This document has been scanned for viruses by Norton Antivirus Security.” This is another example of threat actors’ employing social engineering techniques by impersonating well-known brands, such as established security vendors, to gain the trust of users and increase their likelihood of success.

It is highly probable that a real employee of the law firm had their account hijacked and that a malicious actor was exploiting it to send out these phishing emails en masse as part of a supply chain attack. In such cases, malicious actors rely on their targets’ trust of known contacts to not question departures from their normal conversations. 

Darktrace was able to instantly detect multiple anomalies in these emails, despite the fact that they were seemingly sent by known correspondents. The activity detected automatically triggered model breaches associated with unexpected and visually prominent links. As a result, Darktrace/Email responded by locking the link, stopping users from being able to click it.

Darktrace subsequently identified additional emails from this sender attempting to target other recipients within the company, triggering the model breaches associated with a surge in email sending indicative of a phishing campaign. In response, Darktrace/Email autonomously acted and filed these emails as junk. As more emails were detected across the customer’s environment, the anomaly score of the sender increased and Darktrace ultimately held back over 160 malicious emails, safeguarding recipients from potential account compromise.           

The following Darktrace/Email models were breached throughout the course of this phishing campaign:

  • Unusual/Sender Surge 
  • Unusual/Undisclosed Recipients 
  • Antigena Anomaly 
  • Association/Unlikely Recipient Association 
  • Link/Low Link Association 
  • Link/Visually Prominent Link 
  • Link/Visually Prominent Link Unexpected For Sender 
  • Unusual/New Sender Wide Distribution
  • Unusual/Undisclosed Recipients + New Address Known Domain

Conclusion

Social engineering plays a role in many of the major threats challenging current email cyber security, as attackers can use it to manipulate users into transferring money, revealing credentials, clicking malicious links, and more. 

The above threat stories happened before language generating AI became mainstream with the release of ChatGPT in December 2022. Now, it is even easier for malicious actors to generate sophisticated social engineering emails. By using social media posts as input, social engineering emails written by generative AI can be highly targeted and produced at scale. They often avoid the flags users are trained to look for, like poor grammar and spelling mistakes, and can hide payloads or forgo them entirely.

To mitigate the risk of possible social engineering attempts, it is recommended that organizations implement social media policies that advise employees to be cautious of what they post online and enact procedures to verify if fund transfer requests are legitimate.

Yet these policies are not enough on their own. Darktrace/Email can identify suspicious email traits, whether an email is sent from a known correspondent or an unknown sender. With Self-Learning AI, it knows an organization’s users better than any impersonator could. In this way, Darktrace/Email detects anomalies within emails and neutralizes malicious components at machine-speed, stopping attacks at their earliest stages, before employees fall victim. 

Appendices

List of Indicators of Compromise (IoCs)

Domain:

hxxps://ssvilvensstokes[.]app[.]box[.]com/notes/*?s=* - 1st external link (seen in email)

hxxps://hulking-citrine-krypton[.]glitch[.]me/flk.html - 2nd external link, masked behind “OPEN OR ACCESS DOCUMENT HERE”

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.
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Isabelle Cheong
Cyber Security Analyst
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March 19, 2025

Global Technology Provider Transforms Email Threat Detection with Darktrace

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At a glance

  • Within just one month of using Darktrace / EMAIL, the volume of suspicious emails requiring analyst attention dropped by 75%, saving analysts 45 hours per month on analysis and investigation.
  • By offloading most manual, repetitive tasks to Darktrace / EMAIL, the company’s skilled security analysts can focus on developing new capabilities and tackling more complex, rewarding projects.
  • Darktrace recently detected and blocked a highly sophisticated and personalized phishing email that spoofed a Microsoft SharePoint and Teams website and used advanced engineering to impersonate the school of an employee’s family member.
  • The transition from the incumbent solution to Darktrace / EMAIL was seamless and undetectable to the company’s vast of customers and partners, reinforcing the security organization’s role as a business enabler—protecting the company and reducing risk without adding friction.

Securing a complex, distributed business without disruption

The company remains at the forefront of technological innovation and transformation; however, its success and ambitions come with the challenges of managing a distributed global business—balancing digital advancements, existing technology investments, and evolving compliance requirements.

Optimizing a complex tech stack for scalable growth

The organization operates a diverse technology stack spanning Windows, Mac, Linux, and multiple cloud environments, creating a complex and challenging IT landscape. The company’s Chief Information Security Officer (CISO) emphasizes the need for efficiency and agility. “Our goal is to scale and deliver new capabilities without increasing headcount, ensuring that costs remain proportionate to growth.”

Balancing security, governance, and business agility

Committed to responsible practices, this industry leader prioritizes secure and trustworthy technology for its customers who rely on its solutions. “Balancing business agility with governance is a constant challenge," said the CISO. "There’s always a natural push and pull, which I believe is healthy—but achieving the right balance is delicate.”

Protecting critical workflows without impacting productivity

For the organization, email is much more than just a communication tool. “Email plays a critical role in our engineering workflows and is fundamental to how we build our products.” Because of this, the company is extremely cautious about implementing any solution that could introduce friction or disrupt productivity. “There is zero tolerance for disruption, which is why we take a deliberate and methodical approach when evaluating, selecting, and deploying our tools and solutions,” he said.  

More than a vendor: A security partner invested in success

To ensure an optimal security infrastructure, the enterprise security team regularly evaluates market technologies to their existing solutions. With the rapidly evolving threat landscape, the CISO said they “wanted to validate whether we still had best-in-class protection and the right controls in place to secure our organization. It was about assessing whether we could do better in our ongoing effort to fine-tuning our approach to achieve the best possible outcome.”

The team evaluated 15 different email security vendors based on the following criteria:

  1. Efficacy to detect threats
  2. Ability to integrate with existing tooling
  3. Ease of use
  4. A vendor’s approach to partnership  

They initially narrowed the list to five vendors, conducting demo sessions for deeper evaluations before selecting three finalists for a proof of value (POV). We analyzed actual malicious emails with each vendor to assess the accuracy of their detections, allowing for an objective comparison,” said the CISO. Through this rigorous process, the Darktrace / EMAIL security solution emerged as the best fit for their business. “Darktrace’s product performed well and showed a genuine commitment to partnering with us in the long-term to ensure our success.”

The team objectively understood where there were gaps across the different vendors, where they were strong, and where they could use improvement. “Based on the analysis, we knew that Darktrace / EMAIL could deliver as the data supported it, in our specific use cases.  

Partnership, integrity and respect

Throughout the evaluation process, the importance of partnership and mutual respect remained an essential factor to the CISO. “I wanted a company we could develop a long-term strategic partnership with, one that could extend far deeper than just email.” A key factor in choosing Darktrace was the commitment and engagement of its team at every level of the organization. “Darktrace showed integrity, patience and a genuine investment in building a strong relationship with my team.  That's why we're here today.”

“Together, we've delivered some fantastic outcomes”

For the organization, Darktrace / EMAIL has played a crucial role in reducing risk, empowering analysts, and enabling a lean, effective security strategy. “Together, we've delivered some fantastic outcomes,” said the CISO.  

Reducing risk. Empowering analysts

“Within that first month, we saw a 75% drop in suspicious emails that that required manual review, which reduced the time my team spent analyzing and investigating by 45 hours per month,” said the CISO. The security team values Darktrace / EMAIL not only for its ease of use but also for the time it frees up for more meaningful work. “Giving my team the opportunity to tackle complex challenges they enjoy and find more stimulating is important to me.” As they continue to fine-tune and optimize balance levels within Darktrace / EMAIL, he expects even greater efficiency gains in the coming months.

Maximizing protection while staying lean

It’s important for the security group to be proportionate with their spending, said the CISO. “It's all about what is enough security to enable the business. And that means, as our organization grows, it's important that we are as lean and as efficient as possible to deliver the best outcomes for the business.”  Embracing an AI-powered automated approach is an essential component to achieving that goal. By offloading most manual, repetitive tasks to Darktrace / EMAIL, the company’s skilled security analysts can focus on more strategic and proactive initiatives that enable the business.  

Protecting employees from advanced social engineering threats

Recently, Darktrace detected a malicious email targeting an employee, disguised as a spoofed Microsoft SharePoint and Teams website. What made this attack particularly sophisticated was its personalization — it impersonated the school where the employee’s family member attended. Unlike mass malicious emails sent to thousands of people, this was a highly targeted attack, leveraging advanced social engineering tactics to exploit connections within the education system and between family members.  

Protecting without disrupting

A seamless migration is often overlooked but is critical to success for any organization, said the CISO. With a wide ecosystem of partners, email is a highly visible, business-critical function for the organization — "any friction or downtime would have an immediate impact and could throttle the entire business,” he said. However, the transition from their previous solution to Darktrace / EMAIL was exceptionally smooth. “No one realized we changed providers because there was no disruption — no incidents at all. I cannot emphasize just how important that is when I'm trying to position our security organization as an enabling function for the business that protects and reduces risk without adding friction.”

A security partnership for the future

“To survive as a business over the next few years, adopting AI is no longer optional—it’s essential,” said the CISO. However, with the cybersecurity market becoming increasingly saturated, selecting the right solutions and vendors can be overwhelming. He stresses the importance of choosing strategic partners who not only deliver the outcomes you need, but also deeply understand your organization’s unique environment. “You’re only as strong as your partners. Technology innovation and the cybersecurity market are always changing.  At some point every solution will face a challenge—it’s inevitable. The differentiator will be how people respond when that happens.”  

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March 19, 2025

Survey findings: How is AI Impacting the SOC?

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There’s no question that AI is already impacting the SOC – augmenting, assisting, and filling the gaps left by staff and skills shortages. We surveyed over 1,500 cybersecurity professionals from around the world to uncover their attitudes to AI cybersecurity in 2025. Our findings revealed striking trends in how AI is changing the way security leaders think about hiring and SOC transformation. Download the full report for the big picture, available now.

Download the full report to explore these findings in depth

The AI-human conundrum

Let’s start with some context. As the cybersecurity sector has rapidly evolved to integrate AI into all elements of cyber defense, the pace of technological advancement is outstripping the development of necessary skills. Given the ongoing challenges in security operations, such as employee burnout, high turnover rates, and talent shortages, recruiting personnel to bridge these skills gaps remains an immense challenge in today’s landscape.

But here, our main findings on this topic seem to contradict each other.

There’s no question over the impact of AI-powered threats – nearly three-quarters (74%) agree that AI-powered threats now pose a significant challenge for their organization.  

When we look at how security leaders are defending against AI-powered threats, over 3 out of 5 (62%) see insufficient personnel to manage tools and alerts as the biggest barrier.  

Yet at the same time, increasing cyber security staff is at the bottom of the priority list for survey participants, with only 11% planning to increase cybersecurity staff in 2025 – less than in 2024. What 64% of stakeholders are committed to, however, is adding new AI-powered tools onto their existing security stacks.

With burnout pervasive, the talent deficit reaching a new peak, and growing numbers of companies unable to fill cybersecurity positions, it may be that stakeholders realize they simply cannot hire enough personnel to solve this problem, no matter how much they may want to. As a result, leaders are looking for methods beyond increasing staff to overcome security obstacles.

Meanwhile, the results show that defensive AI is becoming integral to the SOC as a means of augmenting understaffed teams.

How is AI plugging skills shortages in the SOC?

As explored in our recent white paper, the CISO’s Guide to Navigating the Cybersecurity Skills Shortage, 71% of organizations report unfilled cybersecurity positions, leading to the estimation that less than 10% of alerts are thoroughly vetted. In this scenario, AI has become an essential multiplier to relieve the burden on security teams.

95% of respondents agree that AI-powered solutions can significantly improve the speed and efficiency of their defenses. But how?

The area security leaders expect defensive AI to have the biggest impact is on improving threat detection, followed by autonomous response to threats and identifying exploitable vulnerabilities.

Interestingly, the areas that participants ranked less highly (reducing alert fatigue and running phishing simulation), are the tasks that AI already does well and can therefore be used already to relieve the burden of manual, repetitive work on the SOC.

Different perspectives from different sides of the SOC

CISOs and SecOps teams aren’t necessarily aligned on the AI defense question – while CISOs tend to see it as a strategic game-changer, SecOps teams on the front lines may be more sceptical, wary of its real-world reliability and integration into workflows.  

From the data, we see that while less than a quarter of execs doubt that AI-powered solutions will block and automatically respond to AI threats, about half of SecOps aren’t convinced. And only 17% of CISOs lack confidence in the ability of their teams to implement and use AI-powered solutions, whereas over 40% those in the team doubt their own ability to do so.

This gap feeds into the enthusiasm that executives share about adding AI-driven tools into the stack, while day-to-day users of the tools are more interested in improving security awareness training and improving cybersecurity tool integration.

Levels of AI understanding in the SOC

AI is only as powerful as the people who use it, and levels of AI expertise in the SOC can make or break its real-world impact. If security leaders want to unlock AI’s full potential, they must bridge the knowledge gap—ensuring teams understand not just the different types of AI, but where it can be applied for maximum value.

Only 42% of security professionals are confident that they fully understand all the types of AI in their organization’s security stack.

This data varies between job roles – executives report higher levels of understanding (60% say they know exactly which types of AI are being used) than participants in other roles. Despite having a working knowledge of using the tools day-to-day, SecOps practitioners were more likely to report having a “reasonable understanding” of the types of AI in use in their organization (42%).  

Whether this reflects a general confidence in executives rather than technical proficiency it’s hard to say, but it speaks to the importance of AI-human collaboration – introducing AI tools for cybersecurity to plug the gaps in human teams will only be effective if security professionals are supported with the correct education and training.  

Download the full report to explore these findings in depth

The full report for Darktrace’s State of AI Cybersecurity is out now. Download the paper to dig deeper into these trends, and see how results differ by industry, region, organization size, and job title.  

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