Employee Uses Rogue Devices & Attempts to Steal Passwords
26
Nov 2017
Learn how Darktrace detected rogue devices on the network of a healthcare provider and how Darktrace ensured no users fell victim to the attack.
Darktrace recently detected two rogue devices on the network of a major healthcare provider. They were brought onto the network by a trusted employee, who – for reasons still unknown – was attempting to harvest user credentials and profile the network’s defenses.
Darktrace’s AI algorithms had built a detailed understanding of the organization’s normal network activity and digital infrastructure. When the two new devices entered the network and sent ‘Redirect Datagram for the host’ messages to the subnet router, Darktrace identified the anomaly and raised an alert in real time. This represented the first of three anomalies:
Two unknown Raspberry Pis are introduced to the network Based on the MAC addresses, the newly introduced devices were determined to be two Raspberry Pis. Once on the network, they began acting like gateways, which use remote hosts to send data packets on alternative routes.
It was initially believed that the insider was using the devices to engage in ARP spoofing. However, the subnet router did not respond to the messages.
The devices attempt to redirect users to a fake security survey The second anomaly occurred when the devices began beaconing to a rare external endpoint, which resolved to Amazon cloud services. This activity is typically seen in attempted communications with a command-and-control center, but there was no returning inbound traffic.
Instead, the rare destination turned out to be a website, which was identical to an internal website being used to host a security survey. Before accessing the survey, employees needed to enter their user credentials.
In addition to harvesting user credentials, the survey was asking a series of questions that would have been extremely useful for an attacker. The survey included questions designed to learn the status of their anti-virus and firewalls, and whether users were using the same passwords across multiple services.
The insider tries to hide the devices via DHCP allocation requests The final anomaly came when one of the devices made a DHCP allocation request for an IP address on a separate subnet. It had the same hostname of the infringing device, but a new MAC address.
Essentially, the insider was attempting to hide the devices by manually changing their IP addresses through DHCP release and allocation requests.
Each of these anomalies represented a subtle deviation from the organization’s normal ‘pattern of life’. By correlating these weak indicators of threat, Darktrace was able to discover a larger pattern that revealed the whole story: a malicious insider had smuggled Raspberry Pis onto the network to lure users to a fake website, steal their credentials, and test the network’s defenses, all while remaining hidden from network defenses.
By raising alerts in real time, Darktrace helped ensure that no users fell victim to the attack. Soon after, the Pis disappeared from the network. While the culprit was never caught, the organization has yet to experience a similar threat, indicating that the insider either left the organization, or remains in hiding.
Since the incident, the healthcare provider has undergone a restructuring of its network, and they’ve adopted a host of new IoT devices. Darktrace’s algorithms are continuously learning and re-learning normal, so if the malicious insider were to re-emerge, Darktrace would immediately detect their presence on the network.
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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.
Author
Andrew Tsonchev
VP, Security & AI Strategy, Field CISO
Andrew is VP, Security & AI Strategy, Field CISO and advises Darktrace’s strategic customers on advanced threat defense, AI and autonomous response. He has a background in threat analysis and research, and holds a first-class degree in physics from Oxford University and a first-class degree in philosophy from King’s College London. His comments on cyber security and the threat to critical national infrastructure have been reported in international media, including CNBC and the BBC World.
Reimagining Your SOC: Overcoming Alert Fatigue with AI-Led Investigations
The efficiency of a Security Operations Center (SOC) hinges on its ability to detect, analyze and respond to threats effectively. With advancements in AI and automation, key early SOC team metrics such as Mean Time to Detect (MTTD) have seen significant improvements:
96% of defenders believing AI-powered solutions significantly boost the speed and efficiency of prevention, detection, response, and recovery.
Organizations leveraging AI and automation can shorten their breach lifecycle by an average of 108 days compared to those without these technologies.
While tool advances have improved performance and effectiveness in the detection phase, this has not been as beneficial to the next step of the process where initial alerts are investigated further to determine their relevance and how they relate to other activities. This is often measured with the metric Mean Time to Analysis (MTTA), although some SOC teams operate a two-level process with teams for initial triage to filter out more obviously uninteresting alerts and for more detailed analysis of the remainder. SOC teams continue to grapple with alert fatigue, overwhelmed analysts, and inefficient triage processes, preventing them from achieving the operational efficiency necessary for a high-performing SOC.
Addressing this core inefficiency requires extending AI's capabilities beyond detection to streamline and optimize the following investigative workflows that underpin effective analysis.
Challenges with SOC alert investigation
Detecting cyber threats is only the beginning of a much broader challenge of SOC efficiency. The real bottleneck often lies in the investigation process.
Detection tools and techniques have evolved significantly with the use of machine learning methods, improving early threat detection. However, after a detection pops up, human analysts still typically step in to evaluate the alert, gather context, and determine whether it’s a true threat or a false alarm and why. If it is a threat, further investigation must be performed to understand the full scope of what may be a much larger problem. This phase, measured by the mean time to analysis, is critical for swift incident response.
Challenges with manual alert investigation:
Too many alerts
Alerts lack context
Cognitive load sits with analysts
Insufficient talent in the industry
Fierce competition for experienced analysts
For many organizations, investigation is where the struggle of efficiency intensifies. Analysts face overwhelming volumes of alerts, a lack of consolidated context, and the mental strain of juggling multiple systems. With a worldwide shortage of 4 million experienced level two and three SOC analysts, the cognitive burden placed on teams is immense, often leading to alert fatigue and missed threats.
Even with advanced systems in place not all potential detections are investigated. In many cases, only a quarter of initial alerts are triaged (or analyzed). However, the issue runs deeper. Triaging occurs after detection engineering and alert tuning, which often disable many alerts that could potentially reveal true threats but are not accurate enough to justify the time and effort of the security team. This means some potential threats slip through unnoticed.
Understanding alerts in the SOC: Stopping cyber incidents is hard
Let’s take a look at the cyber-attack lifecycle and the steps involved in detecting and stopping an attack:
First we need a trace of an attack…
The attack will produce some sort of digital trace. Novel attacks, insider threats, and attacker techniques such as living-off-the-land can make attacker activities extremely hard to distinguish.
A detection is created…
Then we have to detect the trace, for example some beaconing to a rare domain. Initial detection alerts being raised underpin the MTTD (mean time to detection). Reducing this initial unseen duration is where we have seen significant improvement with modern threat detection tools.
When it comes to threat detection, the possibilities are vast. Your initial lead could come from anything: an alert about unusual network activity, a potential known malware detection, or an odd email. Once that lead comes in, it’s up to your security team to investigate further and determine if this is this a legitimate threat or a false alarm and what the context is behind the alert.
Investigation begins…
It doesn’t just stop at a detection. Typically, humans also need to look at the alert, investigate, understand, analyze, and conclude whether this is a genuine threat that needs a response. We normally measure this as MTTA (mean time to analyze).
Conducting the investigation effectively requires a high degree of skill and efficiency, as every second counts in mitigating potential damage. Security teams must analyze the available data, correlate it across multiple sources, and piece together the timeline of events to understand the full scope of the incident. This process involves navigating through vast amounts of information, identifying patterns, and discerning relevant details. All while managing the pressure of minimizing downtime and preventing further escalation.
Containment begins…
Once we confirm something as a threat, and the human team determines a response is required and understand the scope, we need to contain the incident. That's normally the MTTC (mean time to containment) and can be further split into immediate and more permanent measures.
The challenge is not only in 1) detecting threats quickly, but also 2) triaging and investigating them rapidly and with precision, and 3) prioritizing the most critical findings to avoid missed opportunities. Effective investigation demands a combination of advanced tools, robust workflows, and the expertise to interpret and act on the insights they generate. Without these, organizations risk delaying critical containment and response efforts, leaving them vulnerable to greater impacts.
While there are further steps (remediation, and of course complete recovery) here we will focus on investigation.
Developing an AI analyst: How Darktrace replicates human investigation
Darktrace has been working on understanding the investigative process of a skilled analyst since 2017. By conducting internal research between Darktrace expert SOC analysts and machine learning engineers, we developed a formalized understanding of investigative processes. This understanding formed the basis of a multi-layered AI system that systematically investigates data, taking advantage of the speed and breadth afforded by machine systems.
With this research we found that the investigative process often revolves around iterating three key steps: hypothesis creation, data collection, and results evaluation.
All these details are crucial for an analyst to determine the nature of a potential threat. Similarly, they are integral components of our Cyber AI Analyst which is an integral component across our product suite. In doing so, Darktrace has been able to replicate the human-driven approach to investigating alerts using machine learning speed and scale.
Here’s how it works:
When an initial or third-party alert is triggered, the Cyber AI Analyst initiates a forensic investigation by building multiple hypotheses and gathering relevant data to confirm or refute the nature of suspicious activity, iterating as necessary, and continuously refining the original hypothesis as new data emerges throughout the investigation.
Using a combination of machine learning including supervised and unsupervised methods, NLP and graph theory to assess activity, this investigation engine conducts a deep analysis with incidents raised to the human team only when the behavior is deemed sufficiently concerning.
After classification, the incident information is organized and processed to generate the analysis summary, including the most important descriptive details, and priority classification, ensuring that critical alerts are prioritized for further action by the human-analyst team.
If the alert is deemed unimportant, the complete analysis process is made available to the human team so that they can see what investigation was performed and why this conclusion was drawn.
To illustrate this via example, if a laptop is beaconing to a rare domain, the Cyber AI Analyst would create hypotheses including whether this could be command and control traffic, data exfiltration, or something else. The AI analyst then collects data, analyzes it, makes decisions, iterates, and ultimately raises a new high-level incident alert describing and detailing its findings for human analysts to review and follow up.
Cost Savings Equivalent to adding 30 full-time Level 2 analysts without increasing headcount
Minimize Business Risk Takes on the busy work from human analysts and elevates a team’s overall decision making
Improve Security Outcomes Identifies subtle, sophisticated threats through holistic investigations
Unlocking an efficient SOC
To create a mature and proactive SOC, addressing the inefficiencies in the alert investigation process is essential. By extending AI's capabilities beyond detection, SOC teams can streamline and optimize investigative workflows, reducing alert fatigue and enhancing analyst efficiency.
This holistic approach not only improves Mean Time to Analysis (MTTA) but also ensures that SOCs are well-equipped to handle the evolving threat landscape. Embracing AI augmentation and automation in every phase of threat management will pave the way for a more resilient and proactive security posture, ultimately leading to a high-performing SOC that can effectively safeguard organizational assets.
Every relevant alert is investigated
The Cyber AI Analyst is not a generative AI system, or an XDR or SEIM aggregator that simply prompts you on what to do next. It uses a multi-layered combination of many different specialized AI methods to investigate every relevant alert from across your enterprise, native, 3rd party, and manual triggers, operating at machine speed and scale. This also positively affects detection engineering and alert tuning, because it does not suffer from fatigue when presented with low accuracy but potentially valuable alerts.
Retain and improve analyst skills
Transferring most analysis processes to AI systems can risk team skills if they don't maintain or build them and if the AI doesn't explain its process. This can reduce the ability to challenge or build on AI results and cause issues if the AI is unavailable. The Cyber AI Analyst, by revealing its investigation process, data gathering, and decisions, promotes and improves these skills. Its deep understanding of cyber incidents can be used for skill training and incident response practice by simulating incidents for security teams to handle.
Create time for cyber risk reduction
Human cybersecurity professionals excel in areas that require critical thinking, strategic planning, and nuanced decision-making. With alert fatigue minimized and investigations streamlined, your analysts can avoid the tedious data collection and analysis stages and instead focus on critical decision-making tasks such as implementing recovery actions and performing threat hunting.
Stay tuned for part 3/3
Part 3/3 in the Reimagine your SOC series explores the preventative security solutions market and effective risk management strategies.
Bytesize Security: Insider Threats in Google Workspace
What is an insider threat?
An insider threat is a cyber risk originating from within an organization. These threats can involve actions such as an employee inadvertently clicking on a malicious link (e.g., a phishing email) or an employee with malicious intent conducting data exfiltration for corporate sabotage.
Insiders often exploit their knowledge and access to legitimate corporate tools, presenting a continuous risk to organizations. Defenders must protect their digital estate against threats from both within and outside the organization.
For example, in the summer of 2024, Darktrace / IDENTITY successfully detected a user in a customer environment attempting to steal sensitive data from a trusted Google Workspace service. Despite the use of a legitimate and compliant corporate tool, Darktrace identified anomalies in the user’s behavior that indicated malicious intent.
Attack overview: Insider threat
In June 2024, Darktrace detected unusual activity involving the Software-as-a-Service (SaaS) account of a former employee from a customer organization. This individual, who had recently left the company, was observed downloading a significant amount of data in the form of a “.INDD” file (an Adobe InDesign document typically used to create page layouts [1]) from Google Drive.
While the use of Google Drive and other Google Workspace platforms was not unexpected for this employee, Darktrace identified that the user had logged in from an unfamiliar and suspicious IPv6 address before initiating the download. This anomaly triggered a model alert in Darktrace / IDENTITY, flagging the activity as potentially malicious.
Figure 1: A Model Alert in Darktrace / IDENTITY showing the unusual “.INDD” file being downloaded from Google Workspace.
Following this detection, the customer reached out to Darktrace’s Security Operations Center (SOC) team via the Security Operations Support service for assistance in triaging and investigating the incident further. Darktrace’s SOC team conducted an in-depth investigation, enabling the customer to identify the exact moment of the file download, as well as the contents of the stolen documents. The customer later confirmed that the downloaded files contained sensitive corporate data, including customer details and payment information, likely intended for reuse or sharing with a new employer.
In this particular instance, Darktrace’s Autonomous Response capability was not active, allowing the malicious insider to successfully exfiltrate the files. If Autonomous Response had been enabled, Darktrace would have immediately acted upon detecting the login from an unusual (in this case 100% rare) location by logging out and disabling the SaaS user. This would have provided the customer with the necessary time to review the activity and verify whether the user was authorized to access their SaaS environments.
Conclusion
Insider threats pose a significant challenge for traditional security tools as they involve internal users who are expected to access SaaS platforms. These insiders have preexisting knowledge of the environment, sensitive data, and how to make their activities appear normal, as seen in this case with the use of Google Workspace. This familiarity allows them to avoid having to use more easily detectable intrusion methods like phishing campaigns.
Darktrace’s anomaly detection capabilities, which focus on identifying unusual activity rather than relying on specific rules and signatures, enable it to effectively detect deviations from a user’s expected behavior. For instance, an unusual login from a new location, as in this example, can be flagged even if the subsequent malicious activity appears innocuous due to the use of a trusted application like Google Drive.
Credit to Vivek Rajan (Cyber Analyst) and Ryan Traill (Analyst Content Lead)
Appendices
Darktrace Model Detections
SaaS / Resource::Unusual Download Of Externally Shared Google Workspace File
