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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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Company Shuts Down Cyber-attacks with “Flawless” Detection and Response from Darktrace

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Growing pains: Balancing efficiency with risk  

This organization has recently scaled its operations, and numerous acquisitions have significantly boosted the organization’s capabilities and growth. However, this also creates work and high expectations for the organization’s IT and security teams. Within 12 months of an acquisition, the teams must fully integrate each new business onto the company’s platform. “A huge piece of that integration plan is rolling out our security controls,” said the CISO. “While our goal is to connect those facilities up as quickly as possible to drive efficiency, we also need to implement the proper security controls to protect the enterprise.”

Gap beyond the perimeter  

The organization had established strong security measures to safeguard its perimeter; however, the CISO identified a critical gap in real-time network monitoring. If the perimeter were breached, threats were only discovered after an endpoint was compromised and the issue was manually reported.

As digital transformation progresses, the need to adopt advanced technologies is becoming essential, particularly as organizations begin to open up operational environments to greater connectivity. Many processes still rely on traditional methods, and integrating innovative solutions could drive significant improvements in efficiency and productivity. “We’re committed to adopting cutting-edge technologies,” the CISO explained. “But we understood that without more robust network security controls, opening up our operational environments would expose us to heightened risks, including advanced threats like ransomware.”

Building a layered, proactive security strategy with Darktrace  

To close the gap beyond the perimeter, the company embarked on a free trial with Darktrace. The CISO recalls: “The trials were fantastic. It was obvious that Darktrace was exactly what we needed. The Darktrace team was also very knowledgeable and helpful throughout the process, which was impressive.”  

Today, the organization is using a combination of Darktrace solutions for its layered security approach, including:

Detecting unusual behavior with AI  

Darktrace’s use of machine learning and Self-Learning AI is one of the reasons the company chose Darktrace. Instead of teaching an AI system what an ‘attack’ looks like, training it on large data lakes of thousands of organizations’ data, Darktrace AI learns from the company’s own unique data and user activity to learn and create baseline models of what ‘normal’ looks like for their business.

Darktrace can then detect subtle deviations and unusual activity that signals a possible threat. “That fascinated us because what it really means is this technology doesn’t need to know about every single threat because the threat itself isn’t important, it’s the behavior of the activity that’s important. That capability is unique when it when it comes to threat detection,” said the CISO.

Identifying and mitigating high-impact attack paths

The security team appreciated that with Darktrace they could take a more proactive approach to security by exposing high-risk attack paths through modeling and AI risk assessments. Darktrace / Proactive Exposure Management gives them visibility into vulnerable entry points and assets, identifies active risks, and prioritizes the most important security issues to be addressed.

“Specific users and assets within our business have a higher risk of being targeted by a cyber-attack, for example our executives,” said the CISO. “With Darktrace, we get an adversarial view of our risk. We can see the attack path around those potential targets and proactively take measures to mitigate that vulnerability and prevent an attack.”

Driving up productivity while putting the brakes on cyber-attacks  

The security team collaborated with Darktrace to fine tune the models that really fit their business. With Darktrace now automating most of their threat detection and response efforts, productivity has soared, the security team is now focused on delivering greater value to the business and, most importantly, Darktrace proved it could quickly detect and shut down a major cyber-attack–and do so without impacting business operations.

Fueling team productivity with automation and AI

Prior to using Darktrace, the security team had little visibility into potential risks beyond the perimeter. Today, the team has full control and visibility over the network. “My team is now spending 80-90% of their time doing proactive work because Darktrace is managing the vast majority of our detect and response needs. The team really has faith in the Darktrace system,” said the CISO.  

With less time spent on low-level manual tasks, the security team can now focus on higher priority initiatives. For example, they have expanded their internal vulnerability assessments across the entire group. The team couldn’t focus on this additional audit and vulnerability management work if Darktrace wasn’t taking care of most of their security monitoring. “Darktrace has allowed us to move on to these additional kinds of governance projects that we otherwise would have to hire an army of staff to get through”.

Stopping email threats in their tracks

Using Darktrace / EMAIL, the company has identified and blocked a significant percentage of emails that were making it past their native email filters. “Darktrace is especially good at detecting impersonation emails, and we really appreciate its ability to automatically remove suspicious emails directly from a user’s inbox. It adds an extra level of confidence,” said the CISO.

Self-Learning AI understands anomalies within unique communication patterns to stop known and unknown threats. For example, when an employee sent an email to a brand new domain, Darktrace identified the behavior as unusual and inconsistent with baseline models and blocked the email.

Darktrace passes the biggest test of all

In 2024, the company experienced the value of the security system firsthand when attackers exploited a vulnerability in a third-party remote support solution that they was using. This solution provided remote access and tech support capabilities. If successful, the attackers could have infiltrated high-value end points and created their own administrative user, giving them full control over the server.

“We first became aware of the attack when Darktrace notified us of unusual behavior coming from the remote support server,” said the CISO. The attackers were attempting to put backdoors onto the service with the intent of selling access to the highest bidder who would then install ransomware on their servers. It all happened very quickly, as the attackers tried to connect to the internal network and other servers, while also firing off a host of other actions, like PowerShell commands, to escalate their privileges.  

“Darktrace worked flawlessly. There was no chance that ransomware was ever going to come in,” the CISO said. “Even though there was no signature to really look at, Darktrace realized this was not normal behavior for this server, shutting down connections and doing everything it could do to stop the attack.” Within eight hours, the security team identified and stopped the attack, severed its connection to the third-party solution, and completed additional analysis and clean-up. “In addition to our own investigation, third parties like our external SOC and legal department also confirmed that Darktrace performed as expected. We were able to report back to the executive team that there was zero risk that any data or systems were compromised.”

Post-attack, there was no need to make any changes to Darktrace. The team consistently reviews its models and baselines, often collaborating with Darktrace to make adjustments when needed to continuously improve performance. “Because of this relationship and constant engagement with Darktrace’s technical teams, we didn't have to go back and ask: ‘why wasn’t this updated’ or ‘why didn’t this model work.’ The models worked.”

His advice to other organizations facing similar challenges? First, focus on updating, patching, and vulnerability management, and act quickly when vulnerabilities are identified. His second piece of advice: “have an automated detection system like Darktrace in place so you can respond at the speed that these attacks evolve. Humans can no longer keep up with a scripted attack as it moves around and tries to compromise items on your network. You need the right technology to fight these types of attacks.”

Dynamic capabilities for a dynamic future

Real-time playbooks

With a proactive, enterprise-wide security strategy in place, the CISO now has the time to think about future projects and innovations. He’s particularly interested in the idea of generating playbooks on the fly in response to real-time events. He believes cyber-attacks are far too varied for a static playbook to be useful; when an attack strikes, teams need to quickly understand exactly what’s in front of them and how to shut it down. “This fits into our future cybersecurity strategy, and Darktrace is the only company I’ve seen talking about building playbooks dynamically. This kind of technology would really help bring our cybersecurity strategy full circle.”

“Darktrace ’s technology, experience and expertise is helping us staying ahead of cyber-attacks, minimizing our risk and driving greater productivity for our team,” said the CISO. In collaboration with Darktrace, the team have created a security foundation that is both powerful and agile. “While Darktrace is detecting and responding to attacks targeting our business today, we know that it’s always learning, adapting and scaling to ensure we’re protected tomorrow. That gives me peace of mind and the freedom to focus on our future.”

Download the Darktrace / NETWORK Solution Brief

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Protect in real time: Defend against known and emerging threats without relying on historical data or external intelligence.

Full visibility: Gain comprehensive insights across all network environments, including on-premises, cloud, and remote devices.

AI-powered efficiency: Streamline incident response with AI automation, saving time and resources while ensuring minimal disruption to operations.

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December 11, 2024

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Darktrace is Positioned as a Leader in the IDC MarketScape: Worldwide Network Detection and Response 2024 Vendor Assessment

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Darktrace is pleased to announce that we have been positioned as a Leader in the IDC MarketScape: Worldwide Network Detection and Response 2024 Vendor Assessment. We believe this further highlights Darktrace’s position as a pioneer in the NDR market and follows similar recognition from KuppingerCole, who recently named Darktrace as an Overall Leader, Product Leader, Market Leader and Innovation Leader in the KuppingerCole Leadership Compass: Network Detection and Response (2024).

Network Detection and Response (NDR) solutions are uniquely positioned to provide visibility over the core hub of a business and employee activity, analyzing North-South and East-West traffic to identify threats across the modern network. NDR provides a rich and true source of anomalies and goes beyond process level data that is relied on by Endpoint Detection and Response (EDR) agents that do not provide network level visibility and can be misconfigured at any time.1

Metadata from network traffic can be used to detect a variety of different threats based on events such as anomalous port usage, unusual upload/download activity, impossible travel and many other activities. This has been accelerated by the increased usage of user behavioral analytics (UBA) in network security, which establishes statistical baselines about network entities and highlights deviations from expected activity.1

Darktrace is recognized as a Leader in the IDC MarketScape due to our leadership in the market and our pioneering leadership in AI over the past decade, alongside a variety of other unique differentiators and innovations in the NDR industry.

Darktrace / NETWORK™ delivers full visibility, real time threat detection and Autonomous Response capabilities across an organization’s on-premises, cloud, hybrid and virtual environments, including remote worker endpoints.

Unique Approach to AI

Most NDR vendors and network security tools such as IDS/IPS rely on detecting known attacks with historical data and supervised machine learning, leaving organizations blind and vulnerable to novel threats such as zero-days, variants of known attacks, supply chain attacks and insider threats.

These vendors also tend to apply AI models that are trained globally, and are not unique to each organization’s environment, which creates a high number of false positives and alerts that ultimately lack business context.

The IDC MarketScape recognizes that Darktrace takes a differentiated approach in the market with regards to delivering network detection and response capabilities, noting; “Darktrace is unique in that it does not rely on rules and signatures but rather learns what constitutes as normal for an organization and generates alerts when there is a deviation.”1

Darktrace / NETWORK achieves this through the use of Self-Learning AI and unsupervised machine learning to understand what is normal network behavior, continuously analyzing, mapping and modeling every connection to create a full picture of devices, identities, connections and potential attack paths. Darktrace Self-Learning AI autonomously optimizes itself to cut through the noise and quickly surface genuine, prioritized network security incidents – significantly reducing false positives and removing the hassle of needing to continually tuning alerts manually.

Darktrace’s unique approach to AI also extends to the investigation and triage of network alerts with Cyber AI Analyst. Unlike a chat or prompt based LLM, Cyber AI Analyst investigates all relevant alerts in an environment, including third party alerts, autonomously forming hypotheses and reaching conclusions just like a human analyst would, accelerating SOC Level 2 analyses of incidents by 10x. Cyber AI Analyst also typically providing SOC teams with up to 50,000 additional hours annually of Level 2 analysis producing high level alerts and written reporting, transforming security operations.2

Darktrace also uses its deep understanding of what is normal for a network to identify suspicious behavior, leveraging Autonomous Response capabilities to shut down both known and novel threats in real time, taking targeted actions without disrupting business operations. Darktrace / NETWORK is the only NDR solution that can autonomously enforce a pattern of life based on what is normal for a standalone device or group of peers, rapidly containing and disarming threats based on the overall context of the environment and a granular understanding of what is normal for a device or user – instead of relying on historical attack data.

Continued NDR Market Leadership

Darktrace has been recognized as a Leader in the NDR market, and the IDC MarketScape listed a variety of strengths:

  • Darktrace achieves roughly one-fifth of all global NDR revenue. This is important because other IT and cybersecurity solutions providers necessarily want to have integration with Darktrace.
  • The AI algorithms that Darktrace uses for NDR have had 10 years of deployments, tuning, and learning to draw from.
  • Darktrace is available as a SaaS, as an enterprise license, and as physical, hybrid, or virtual appliances. Darktrace also offers an endpoint agent and visibility into VPN and ZTNA.
  • Darktrace integrates with 30+ different interfaces including SIEM, SOAR, XDR platforms, IT ticketing solutions, and their own dashboards. The Darktrace Threat Visualizer highlights events and incidents from the entire deployment including cloud, apps, email, endpoint, zero trust, network, and OT.
  • Darktrace / NETWORK charts the progress that the SOC is making over time with key metrics such as MTTD/MTTR, alerts generated and processed, and other criteria.
  • Darktrace reported coverage of 14 MITRE ATT&CK categories, 158 techniques, and 184 subtechniques

Proactive Network Resilience

The IDC MarketScape notes, “Ultimately, NDR shines as a standalone detection and response technology but is especially powerful when combined with other platforms. NDR in combination with other control points such as endpoint, data, identity, and application provides the proper context when winnowing alerts and trying to uncover a single source of truth.” . Darktrace comprehensively addresses this as part of the ActiveAI Security Platform, by combining network alerts with data from / EMAIL, / IDENTITY, / ENDPOINT, / CLOUD and / OT, providing deeper contextual analysis for each network alert and automatically enriching investigations.

Darktrace also goes beyond NDR solutions with capabilities that are closely linked to our NDR offering, helping clients to achieve and maintain a state of proactive network resilience:

  • Darktrace / Proactive Exposure Management – look beyond just CVE risks to discover, prioritize and validate risks by business impact and how to address them early, reducing the number of real threats that security teams need to handle.
  • Darktrace / Incident Readiness & Recovery – lets teams respond in the best way to each incident and proactively test their familiarity and effectiveness of IR workflows with sophisticated incident simulations based on their own analysts and assets.

Together, these solutions allow Darktrace / NETWORK to go beyond the traditional approach to NDR and shift teams to a more hardened and proactive stance.

Protecting Clients with Continued Innovation

Darktrace invests heavily in Research and Development to continue providing customers with market-leading NDR capabilities and innovations, which was reflected in our position in the Leader category of the MarketScape report for both capabilities and strategy. We are led by the needs and challenges of our customers, which serve as the driving force behind our continued innovation and leadership in the NDR market. The IDC MarketScape report underlines this approach with the following feedback presented by Darktrace customers:

“A customer intimated that 99% of their detections were OOTB with little need to tune or define parameters.”
“A customer reported that it had early warnings for adversarial tactics such as suspicious SMB scanning, suspicious remote execution, remote desktop protocol (RDP) scanning, data exfiltration, C2C, LDAP query, and suspicious Kerberos activity.”
“The client could use Regex to determine if suspicious behavior was found elsewhere on the network.”

Thousands of customers around the world across all industries and sectors rely on Darktrace / NETWORK to protect against known and novel threats. From the latest vulnerabilities in network hardware to sophisticated new strains of ransomware and everything in-between, Darktrace helps clients detect and respond to all types of threats affecting their networks and avoid business disruption, even from the latest attacks.

Find out more about the unique capabilities of Darktrace / NETWORK and our application of AI in network security in the IDC MarketScape excerpt.

References

  1. IDC MarketScape: Worldwide Network Detection and Response 2024 Vendor Assessment (Doc #US51752324, November 2024)
  2. Darktrace Cyber AI Analyst Customer Fleet Data
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About the author
Mikey Anderson
Product Manager, Network Detection & Response
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