Blog
/
Email
/
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
Default blog image
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

Blog

/

Proactive Security

/

June 2, 2026

Stopping Stealth Attacks with Precision: How Núclea Prevented a Breach Without Disruption

Default blog imageDefault blog image

Núclea is a Brazilian data and technology company that supports the country’s financial system by delivering digital services exclusively to banks and financial institutions. Operating in an environment where trust, availability, and data integrity are critical, the company faces a threat landscape that has evolved rapidly—particularly with the rise of AI-driven cyberattacks.

Brazil has experienced a wave of successful cyber incidents targeting financial institutions, many of them enabled by insiders or compromised credentials. The result was a noticeable shift in attacker strategy: instead of focusing on end customers, threat actors began targeting the institutions and platforms that underpin the financial ecosystem itself.

“Attacks became far more directed and contextual,” explains Guilherme, who leads incident response within Núclea’s security platform engineering team. “They weren’t noisy or obviously malicious—they were precise, patient, and designed to blend into normal operations.”

That precision was on full display in January 2026, when Núclea faced one of the most convincing phishing attacks the team had seen.

A real attack, built on trust and context

The attack began with a seemingly routine email.

It was sent from a real Brazilian government institution, using legitimate infrastructure and valid credentials that were later confirmed to have been compromised. Núclea had an established, ongoing relationship with this organization, and the email’s language, tone, and subject matter aligned perfectly with the type of communication the recipient team handled every day.

Attached to the email was a PDF document containing content that looked entirely legitimate.

The problem? A single URL embedded inside that PDF.

“The message itself was correct. The sender was real. The context was familiar. Even the document content made sense,” Guilherme explains. “There was just one small element that didn’t belong.”

That small detail was enough to initiate a full attack chain.

What the attackers were trying to do

If clicked, the URL would have downloaded a malicious payload designed to:

  • Collect information about the user and device
  • Identify where the system was located within the financial ecosystem
  • Install remote access tools to maintain control
  • Deploy an infostealer to extract sensitive data
  • Execute anti-forensic scripts to erase traces of the intrusion

In other words, it was a carefully engineered operation designed for persistence and stealth, not immediate disruption.

The attack also employed urgency—a classic social engineering technique. When the link didn’t open as expected, employees requested assistance from the security team, insisting the document was important and needed to be accessed quickly.

This is precisely the kind of scenario where traditional security tools struggle: almost everything about the interaction is legitimate.

Where Darktrace made the difference

Instead of blocking the entire message or relying on known indicators of compromise, Darktrace focused on behavioral context.

Darktrace recognized:

  • That the sending organization was normally trusted
  • That the communication pattern matched historical behavior
  • That the PDF content itself was not suspicious

But it also identified that the URL embedded within the document deviated from established behavioral patterns.

Rather than disrupting business operations, Darktrace took precise action: it rewrote the URL, preventing the malicious download while leaving the rest of the email untouched.

“When we analyzed it afterward, it became clear how dangerous the attack would have been,” says Guilherme. “But it never progressed—because Darktrace acted at exactly the right point.”

Subsequent forensic analysis confirmed the payload’s malicious intent. The attack never succeeded.

Precision over disruption

For Núclea, this incident reinforced a critical lesson: modern attacks don’t always look malicious—they hide within normal activity.

“What stands out to me is the precision,” Guilherme says. “Darktrace doesn’t rely on big, obvious signals. It’s effective in situations that fall outside the standard patterns we all know.”

Building resilience in a high trust ecosystem

For Núclea, cybersecurity is not just a defensive measure—it’s a business enabler.

Availability failures or successful breaches in the financial ecosystem can have immediate, large-scale consequences, from financial loss to reputational damage. Preventing those outcomes protects not just Núclea, but its partners and customers as well.

“Cyber resilience means keeping the business running—even under attack,” Guilherme explains. “And that requires people, processes, and technology working together.”

As AI continues to accelerate both attacks and defenses, the role of security is evolving. Precision, behavioral understanding, and intelligent automation are no longer optional—they’re essential.

“The easy days were yesterday,” Guilherme says. “The challenges ahead are bigger. We need to be prepared—internally and with partners that help us build resilience.”

Continue reading
About the author

Blog

/

Proactive Security

/

June 1, 2026

Defend What You Trust: Stories from the Front Lines of Modern Cyber Defense

Default blog imageDefault blog image

Modern attacks don’t always announce themselves, follow obvious patterns, or rely on known malware. Often, they move quietly inside trusted systems, authenticated sessions, and everyday behavior.

They don’t break in. They blend in.

That’s why an AI-powered defense is essential. It turns invisible signals into actionable insights at a scale neither analysts nor traditional tools can achieve alone.

Confidence is creating risk

One of the most dangerous assumptions in cybersecurity today is that strong controls equal strong protection.

Multi-factor authentication (MFA), for example, is widely viewed as a foundational safeguard. But as the CISO for a professional sports organization explains, that confidence can be misplaced. “A lot of organizations assume that once you have MFA, those accounts are safe. That’s not true.”

In one instance, his team identified a sophisticated attack where a threat actor bypassed MFA entirely, not by breaking it, but by going around it. A user’s authenticated session was hijacked and re-used, allowing the attacker to impersonate them without triggering traditional controls.

“Darktrace picked up that a session had been re-injected by the hacker, and we were able to block it right away,” he explains.

Attackers anticipate what we miss

Even well-trained users can become entry points.

“An email bypassed our existing security tools,” shares the VP of IT at a U.S.-based risk management services provider.  “The user missed one signal and entered their credentials into a malicious site. That’s what the bad guys count on.”

The organization responded quickly, but not before damage was done. Crucially, this occurred while Darktrace was in “watch mode,” before autonomous response was fully enabled. “Darktrace would have seen that and shut it down immediately,” he notes.

Mistakes and oversights like misconfigurations, forgotten machines, and missed patches can create serious vulnerabilities.

The CIO of a utility services organization shares an instance when Darktrace detected a breach to a client’s network via their ZTNA VPN due to misconfigured MFA. “Darktrace alerted us and autonomously blocked the scanning, preventing what could have been a ransomware-type incident.”  

The most dangerous threats are already inside

The Head of Security at a global business services provider knows firsthand how blind spots can persist inside environments. His team uncovered evidence of dormant ransomware artifacts sitting unnoticed within a company’s environment ¬¬– long before modern detection was in place.

“During a routine file transfer, Darktrace flagged the suspicious activity, identified the ransomware, and immediately quarantined the server,” he recalls.  While the attack was never executed, the implication was significant: the risk existed long before it was finally detected.

Cyber threats are also successful because they take advantage of normal human behavior, exploiting moments of cognitive overload, urgency, and trust.

The Executive Director of IT and Business Applications at a pharmaceutical lab describes the time Darktrace flagged an employee logging into Microsoft 365 from Singapore, despite him being physically located in the U.S. Darktrace immediately cut off his access and within minutes revealed that the employee’s son was using a VPN to play a video game.

While the threat was benign, it demonstrated the strength of AI to use contextual information to detect threats other tools miss. The information also saved security analysts hours of investigation and minimized downtime for the employee. “That level of precision and speed isn’t just convenient, it’s game changing.”

“Unusual” behavior is the new red flag

Detecting modern threats requires an understanding of what “normal” looks like and recognizing when something subtly deviates.

One security leader  at an AI technology enterprise described a scenario in which an employee connected to a proxy service in China. The service itself was legitimate, and although traditional tools didn’t flag it, the behavior was unusual for that user specifically.

“That’s what Darktrace picked up on. The activity turned out to be benign, but without visibility into behavioral deviations, it could just as easily have been something more serious.”

AI shifts defense from reaction to anticipation

These stories point to a fundamental shift by cyber attackers, both tactically and strategically. Because traditional security tools were built to detect what’s already known, modern attacks are often:

  • Credential-based, not malware-based
  • Behavioral, not signature-based
  • Subtle, not overt

They may operate within the boundaries of what appears normal, exploiting what organizations trust, not what they block:

  • Trusted sessions
  • Legitimate services
  • Human error

This is where AI is changing the equation. Rather than relying on predefined rules or known threat signatures, AI can:

  • Establish a baseline of normal behavior
  • Detect subtle anomalies in real time
  • Act autonomously to contain potential threats

Resilience, not perfection, is the new security standard

As these frontline experiences show, the organizations that lead are those that move beyond reactive defense and embrace AI as a core part of their strategy.

It eliminates the blind spots and uncertainty, says the CISO of a professional sports organization. “If you lack visibility, you’re not managing risk, you’re assuming it. AI gives you the actionable insights needed to turn uncertainty into control.”

And it provides the speed and agility that are vital when seconds matter, says the Executive Director of IT and Business Applications. “When Darktrace alerted us at 3:00 am to a ransomware attack, it had already quarantined the affected systems, blocked the attacker’s access, and provided us with the critical details and time needed to investigate. That action likely saved us hundreds of thousands, if not millions, of dollars.”

The modern SOC has become a cornerstone of enterprise resilience, responsible for protecting data and operational continuity while enabling digital growth and innovation. For today’s security professional, that means success is no longer measured by what they keep out, but by what they protect: revenue, reputation, and trust.

Continue reading
About the author
Your data. Our AI.
Elevate your network security with Darktrace AI