Darktrace Antigena allows your security team to take the time they need to investigate malicious behavior. Learn how this can benefit your cyber security!
“The next phase in our journey toward autonomous security is Autonomous Response decision-making.”
Lawrence Pingree, Research Vice President, Gartner
We’ve talked extensively on this blog about Autonomous Response: the AI-powered technology that, according to Gartner, represents a paradigm shift in cyber defense. As the first such Autonomous Response tool, Darktrace Antigena has already thwarted countless cyber-attacks, from a spear phishing campaign against a major city to an IoT smart locker attack targeting a popular amusement park. Antigena’s surgical intervention afforded their security teams the time they needed to investigate — stopping the clock in seconds by containing just the malicious behavior.
For all its benefits, however, Autonomous Response does have one drawback: it can make for slightly anticlimactic blog posts. In place of captivating, step-by-step descriptions of malware spreading throughout the enterprise and inflicting irrevocable damage, Antigena case studies end a mere moment after they start, with the “patient zero” employee completely unaware of the compromise that could have been.
In this particular case, however, Antigena was deployed in Human Confirmation Mode — a starter mode wherein the AI’s actions must first be approved by the security team. Absent such approval, the result was both an in-depth look at a sophisticated ransomware attack, as well as a remarkable illustration of how Antigena reacted in real time to every stage of that attack’s lifecycle:
Initial download
Patient zero here was a device that Darktrace detected downloading an executable file from a server with which no other devices on the network had ever communicated. Downloads like this one regularly bypass conventional endpoint tools, since they cannot be programmed in advance to catch the full range of unpredictable future threats. By contrast, because Darktrace AI learned the typical behavior of the company’s unique users and devices while ‘on the job’, it easily determined the download to be anomalous.
Figure 1: Darktrace alerts on the 100% rare connection and subsequent download — as it occurs.
Had Antigena been in Active Mode at the time, this would have marked the end of the blog post. By blocking all connections to the associated IP and port, Antigena would have instantly stopped the download — without otherwise impacting the device at all.
Figure 2: Antigena, in Human Confirmation Mode, recommends that it block the suspicious activity.
Command and control
Following the download, Darktrace observed the device making an HTTP GET request to the same rare endpoint. The continuation of this suspicious activity precipitated an escalation in Antigena’s recommended response, which would now have blocked all outgoing traffic from the breached device to prevent any infection from spreading.
Darktrace then detected the device making yet more unusual external connections to endpoints that, in many cases, had self-signed SSL certificates. Such self-signed certificates do not require verification by a trusted authority and are therefore frequently utilized by cyber-criminals. As a consequence, the outgoing connections from our infected device are likely the installed malware communicating with its command and control infrastructure, as Darktrace flagged below:
Figure 3: Darktrace alerts on the suspicious SSL certificates.
Figure 4: Antigena recommends taking action to block the connections in question.
Internal reconnaissance
Beyond the unusual external activity observed from the breached device, it also began to deviate significantly from its typical pattern of internal behavior. Indeed, Darktrace detected the device making over 160,000 failed internal connections on two key ports: Remote Desktop Protocol port 3389 and SMB port 445. This activity — known as network scanning — provides crucial reconnaissance, giving the attacker insight into the network structure, the services available on each device, and any potential vulnerabilities. Ports 3389 and 445 are especially common targets.
Figure 5: Darktrace tracks this ransomware attack at every step, though the security team does not mount a response in time.
The unusual external connections to self-signed SSL certificates, combined with the highly anomalous internal connectivity from the device, would have caused Antigena to escalate further. Alas, the attack proceeds.
Darktrace detected no further anomalous activity from patient zero for the next four days — perhaps a mechanism to remain under the radar. Yet this period of dormancy concluded when, once again, the device connected to a rare domain with a self-signed SSL certificate, likely reaching out to its command and control infrastructure for additional instructions.
Lateral movement
A day later — in a sign that suggests the prior scanning was somewhat fruitful — the infected device performed a large amount of unusual SMB activity consistent with the malware attempting to move laterally across the network. Darktrace picked up on the breached device sending unusual outgoing SMB writes to the remote administration tool PsExec to a total of 38 destination devices, 28 of which it compromised with a malicious file.
Darktrace recognized this activity as highly anomalous for the particular device, as it doesn’t usually communicate with these destination devices in this manner. Antigena would therefore would have surgically blocked the remote administration behavior by first containing the patient zero device to its normal ‘pattern of life’, and then by escalating to blocking all outgoing connections from the device if lateral movement had continued. Antigena’s escalation can be seen below: the first action is taken at 08:03, the second, more severe action at 08:43.
Figure 6: Darktrace repeatedly alerts on the unusual SMB traffic with high confidence — thanks to its evolving understanding of the device’s typical ‘pattern of life’.
Figure 7: Antigena again recommends immediate intervention, this time to impede lateral movement.
Encryption
Darktrace observed the first sign of the ransomware’s ultimate objective — encrypting files — on a different device, which also performed a large volume of unusual SMB activity. After accessing a multitude of SMB shares that it hadn’t accessed previously, it systematically appended those files with the .locked extension. When all was said and done, this encryption activity was seen from no less than 40 internal devices.
In Active Mode, Antigena Ransomware Block would have fully quarantined the devices — a culmination of increasingly severe Antigena actions from the initial infection of patient zero, to the command and control communication, to the internal reconnaissance, to the lateral movement, and finally to the file encryption.
Figure 8: Antigena Ransomware Block was fully armed and prepared to fight back against the infection.
The case for boring blog posts
No other approach to cyber security is able to track ransomware so comprehensively throughout its lifecycle, as programming legacy tools to flag all remote administration behavior, for instance, would inundate security teams with thousands of false positive alerts. Thus, only Darktrace’s understanding ‘self’ for each infected device can shed light on such activities — in the rare cases when they are anomalous.
Figure 9: An overview of Darktrace’s myriad warnings throughout the five-day attack with each colored dot representing a high-confidence alert.
However, intriguing though it may be to track this lifecycle to conclusion, the technology to write far less intriguing blog posts already exists and is already proven. Autonomous Response will render this kind of threat story a relic of the past, and for organizations with sensitive data and critical intellectual property to safeguard, the days of boring security blogs cannot come soon enough.
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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
Max Heinemeyer
Chief Product Officer
Max is a cyber security expert with over a decade of experience in the field, specializing in a wide range of areas such as Penetration Testing, Red-Teaming, SIEM and SOC consulting and hunting Advanced Persistent Threat (APT) groups. At Darktrace, Max is closely involved with Darktrace’s strategic customers & prospects. He works with the R&D team at Darktrace, shaping research into new AI innovations and their various defensive and offensive applications. Max’s insights are regularly featured in international media outlets such as the BBC, Forbes and WIRED. Max holds an MSc from the University of Duisburg-Essen and a BSc from the Cooperative State University Stuttgart in International Business Information Systems.
Navigating buying and adoption journeys for AI cybersecurity tools
Enterprise AI tools go mainstream
In this dawning Age of AI, CISOs are increasingly exploring investments in AI security tools to enhance their organizations’ capabilities. AI can help achieve productivity gains by saving time and resources, mining intelligence and insights from valuable data, and increasing knowledge sharing and collaboration.
While investing in AI can bring immense benefits to your organization, first-time buyers of AI cybersecurity solutions may not know where to start. They will have to determine the type of tool they want, know the options available, and evaluate vendors. Research and understanding are critical to ensure purchases are worth the investment.
Challenges of a muddied marketplace
Key challenges in AI purchasing come from consumer doubt and lack of vendor transparency. The AI software market is buzzing with hype and flashy promises, which are not necessarily going to be realized immediately. This has fostered uncertainty among potential buyers, especially in the AI cybersecurity space.
As Gartner writes, “There is a general lack of transparency and understanding about how AI-enhanced security solutions leverage AI and the effectiveness of those solutions within real-world SecOps. This leads to trust issues among security leaders and practitioners, resulting in slower adoption of AI features” [1].
Given this widespread uncertainty generated through vague hype, buyers must take extra care when considering new AI tools to adopt.
Goals of AI adoption
Buyers should always start their journeys with objectives in mind, and a universal goal is to achieve return on investment. When organizations adopt AI, there are key aspects that will signal strong payoff. These include:
Wide-ranging application across operations and areas of the business
Actual, enthusiastic adoption and application by the human security team
Integration with the rest of the security stack and existing workflows
Business and operational benefits, including but not limited to:
Reduced risk
Reduced time to response
Reduced potential downtime, damage, and disruption
Increased visibility and coverage
Improved SecOps workflows
Decreased burden on teams so they can take on more strategic tasks
Ideally, most or all these measurements will be fulfilled. It is not enough for AI tools to benefit productivity and workflows in theory, but they must be practically implemented to provide return on investment.
Investigation before investment
Before investing in AI tools, buyers should ask questions pertaining to each stage of the adoption journey. The answers to these questions will not only help buyers gauge if a tool could be worth the investment, but also plan how the new tool will practically fit into the organization’s existing technology and workflows.
Figure 1: Initial questions to consider when starting to shop for AI [2].
These questions are good to imagine how a tool will fit into your organization and determine if a vendor is worth further evaluation. Once you decide a tool has potential use and feasibility in your organization, it is time to dive deeper and learn more.
Ask vendors specific questions about their technology. This information will most likely not be on their websites, and since it involves intellectual property, it may require an NDA.
Find a longer list of questions to ask vendors and what to look for in their responses in the white paper “CISO’s Guide to Buying AI.”
Committing to transparency amidst the AI hype
For security teams to make the most out of new AI tools, they must trust the AI. Especially in an AI marketplace full of hype and obfuscation, transparency should be baked into both the descriptions of the AI tool and the tool’s functionality itself. With that in mind, here are some specifics about what techniques make up Darktrace’s AI.
Darktrace as an AI cybersecurity vendor
Darktrace has been using AI technology in cybersecurity for over 10 years. As a pioneer in the space, we have made innovation part of our process.
The Darktrace ActiveAI Security Platform™ uses multi-layered AI that trains on your unique business operations data for tailored security across the enterprise. This approach ensures that the strengths of one AI technique make up for the shortcomings of another, providing well-rounded and reliable coverage. Our models are always on and always learning, allowing your team to stop attacks in real time.
The machine learning techniques used in our solution include:
Unsupervised machine learning
Multiple Clustering Techniques
Multiple anomaly detection models in tandem analyzing data across hundreds of metrics
Bayesian probabilistic methods
Bayesian metaclassifier for autonomous fine-tuning of unsupervised machine learning models
Deep learning engines
Graph theory
Applied supervised machine learning for investigative AI
Neural networks
Reinforcement Learning
Generative and applied AI
Natural Language Processing (NLP) and Large Language Models (LLMs)
Post-processing models
Additionally, since Darktrace focuses on using the customer’s data across its entire digital estate, it brings a range of advantages in data privacy, interpretability, and data transfer costs.
Building trust with Darktrace AI
Darktrace further supports the human security team’s adoption of our technology by building trust. To do that, we designed our platform to give your team visibility and control over the AI.
Instead of functioning as a black box, our products focus on interpretability and sharing confidence levels. This includes specifying the threshold of what triggered a certain alert and the details of the AI Analyst’s investigations to see how it reached its conclusions. The interpretability of our AI uplevels and upskills the human security team with more information to drive investigations and remediation actions.
For complete control, the human security team can modify all the detection and response thresholds for our model alerts to customize them to fit specific business preferences.
Conclusion
CISO’s are increasingly considering investing in AI cybersecurity tools, but in this rapidly growing field, it’s not always clear what to look for.
Buyers should first determine their goals for a new AI tool, then research possible vendors by reviewing validation and asking deeper questions. This will reveal if a tool is a good match for the organization to move forward with investment and adoption.
As leaders in the AI cybersecurity industry, Darktrace is always ready to help you on your AI journey.
Learn more about the most common types of machine learning in cybersecurity in the white paper “CISO’s Guide to Buying AI.”
References
Gartner, April 17, 2024, “Emerging Tech: Navigating the Impact of AI on SecOps Solution Development.”
Triaging Triada: Understanding an Advanced Mobile Trojan and How it Targets Communication and Banking Applications
The rise of android malware
Recently, there has been a significant increase in malware strains targeting mobile devices, with a growing number of Android-based malware families, such as banking trojans, which aim to steal sensitive banking information from organizations and individuals worldwide.
These malware families attempt to access users’ accounts to steal online banking credentials and cookies, bypass multi-factor authentication (MFA), and conduct automatic transactions to steal funds [1]. They often masquerade as legitimate software or communications from social media platforms to compromise devices. Once installed, they use tactics such as keylogging, dumping cached credentials, and searching the file system for stored passwords to steal credentials, take over accounts, and potentially perform identity theft [1].
One recent example is the Antidot Trojan, which infects devices by disguising itself as an update page for Google Play. It establishes a command-and-control (C2) channel with a server, allowing malicious actors to execute commands and collect sensitive data [2].
Despite these malware’s ability to evade detection by standard security software, for example, by changing their code [3], Darktrace recently detected another Android malware family, Triada, communicating with a C2 server and exfiltrating data.
Triada: Background and tactics
First surfacing in 2016, Triada is a modular mobile trojan known to target banking and financial applications, as well as popular communication applications like WhatsApp, Facebook, and Google Mail [4]. It has been deployed as a backdoor on devices such as CTV boxes, smartphones, and tablets during the supply chain process [5]. Triada can also be delivered via drive-by downloads, phishing campaigns, smaller trojans like Leech, Ztorg, and Gopro, or more recently, as a malicious module in applications such as unofficial versions of WhatsApp, YoWhatsApp, and FM WhatsApp [6] [7].
How does Triada work?
Once downloaded onto a user’s device, Triada collects information about the system, such as the device’s model, OS version, SD card space, and list of installed applications, and sends this information to a C2 server. The server then responds with a configuration file containing the device’s personal identification number and settings, including the list of modules to be installed.
After a device has been successfully infected by Triada, malicious actors can monitor and intercept incoming and outgoing texts (including two-factor authentication messages), steal login credentials and credit card information from financial applications, divert in-application purchases to themselves, create fake messaging and email accounts, install additional malicious applications, infect devices with ransomware, and take control of the camera and microphone [4] [7].
For devices infected by unofficial versions of WhatsApp, which are downloaded from third-party app stores [9] and from mobile applications such as Snaptube and Vidmate , Triada collects unique device identifiers, information, and keys required for legitimate WhatsApp to work and sends them to a remote server to register the device [7] [12]. The server then responds by sending a link to the Triada payload, which is downloaded and launched. This payload will also download additional malicious modules, sign into WhatsApp accounts on the target’s phone, and request the same permissions as the legitimate WhatsApp application, such as access to SMS messages. If granted, a malicious actor can sign the user up for paid subscriptions without their knowledge. Triada then collects information about the user’s device and mobile operator and sends it to the C2 server [9] [12].
How does Triada avoid detection?
Triada evades detection by modifying the Zygote process, which serves as a template for every application in the Android OS. This enables the malware to become part of every application launched on a device [3]. It also substitutes system functions and conceals modules from the list of running processes and installed apps, ensuring that the system does not raise the alarm [3]. Additionally, as Triada connects to a C2 server on the first boot, infected devices remain compromised even after a factory reset [4].
Triada attack overview
Across multiple customer deployments, devices were observed making a large number of connections to a range of hostnames, primarily over encrypted SSL and HTTPS protocols. These hostnames had never previously been observed on the customers’ networks and appear to be algorithmically generated. Examples include “68u91.66foh90o[.]com”, “92n7au[.]uhabq9[.]com”, “9yrh7.mea5ms[.]com”, and “is5jg.3zweuj[.]com”.
Figure 1: External Sites Summary Graph showing the rarity of the hostname “92n7au[.]uhabq9[.]com” on a customer network.
Most of the IP addresses associated with these hostnames belong to an ASN associated with the cloud provider Alibaba (i.e., AS45102 Alibaba US Technology Co., Ltd). These connections were made over a range of high number ports over 1000, most commonly over 30000 such as 32091, which Darktrace recognized as extremely unusual for the SSL and HTTPS protocols.
Figure 2: Screenshot of a Model Alert Event log showing a device connecting to the endpoint “is5jg[.]3zweuj[.]com” over port 32091.
On several customer deployments, devices were seen exfiltrating data to hostnames which also appeared to be algorithmically generated. This occurred via HTTP POST requests containing unusual URI strings that were made without a prior GET request, indicating that the infected device was using a hardcoded list of C2 servers.
Figure 3: Screenshot of a Model Alert Event Log showing the device posting the string “i8xps1” to the hostname “72zf6.rxqfd[.]com.
Figure 4: Screenshot of a Model Alert Event Log showing the device posting the string “sqyjyadwwq” to the hostname “9yrh7.mea5ms[.]com”.
These connections correspond with reports that devices affected by Triada communicate with the C2 server to transmit their information and receive instructions for installing the payload.
A number of these endpoints have communicating files associated with the unofficial WhatsApp versions YoWhatsApp and FM WhatsApp [11] [12] [13] . This could indicate that the devices connecting to these endpoints were infected via malicious modules in the unofficial versions of WhatsApp, as reported by open-source intelligence (OSINT) [10] [12]. It could also mean that the infected devices are using these connections to download additional files from the C2 server, which could infect systems with additional malicious modules related to Triada.
Moreover, on certain customer deployments, shortly before or after connecting to algorithmically generated hostnames with communicating files linked to YoWhatsApp and FM WhatsApp, devices were also seen connecting to multiple endpoints associated with WhatsApp and Facebook.
Figure 5: Screenshot from a device’s event log showing connections to endpoints associated with WhatsApp shortly after it connected to “9yrh7.mea5ms[.]com”.
These surrounding connections indicate that Triada is attempting to sign in to the users’ WhatsApp accounts on their mobile devices to request permissions such as access to text messages. Additionally, Triada sends information about users’ devices and mobile operators to the C2 server.
The connections made to the algorithmically generated hostnames over SSL and HTTPS protocols, along with the HTTP POST requests, triggered multiple Darktrace models to alert. These models include those that detect connections to potentially algorithmically generated hostnames, connections over ports that are highly unusual for the protocol used, unusual connectivity over the SSL protocol, and HTTP POSTs to endpoints that Darktrace has determined to be rare for the network.
Conclusion
Recently, the use of Android-based malware families, aimed at stealing banking and login credentials, has become a popular trend among threat actors. They use this information to perform identity theft and steal funds from victims worldwide.
Across affected customers, multiple devices were observed connecting to a range of likely algorithmically generated hostnames over SSL and HTTPS protocols. These devices were also seen sending data out of the network to various hostnames via HTTP POST requests without first making a GET request. The URIs in these requests appeared to be algorithmically generated, suggesting the exfiltration of sensitive network data to multiple Triada C2 servers.
This activity highlights the sophisticated methods used by malware like Triada to evade detection and exfiltrate data. It underscores the importance of advanced security measures and anomaly-based detection systems to identify and mitigate such mobile threats, protecting sensitive information and maintaining network integrity.
Credit to: Justin Torres (Senior Cyber Security Analyst) and Charlotte Thompson (Cyber Security Analyst).
Appendices
Darktrace Model Detections
Model Alert Coverage
Anomalous Connection / Application Protocol on Uncommon Port
Anomalous Connection / Multiple Connections to New External TCP Port
Anomalous Connection / Multiple HTTP POSTS to Rare Hostname
Anomalous Connections / Multiple Failed Connections to Rare Endpoint
Anomalous Connection / Suspicious Expired SSL
Compromise / DGA Beacon
Compromise / Domain Fluxing
Compromise / Fast Beaconing to DGA
Compromise / Sustained SSL or HTTP Increase
Compromise / Unusual Connections to Rare Lets Encrypt
Unusual Activity / Unusual External Activity
AI Analyst Incident Coverage
Unusual Repeated Connections to Multiple Endpoints
![External Sites Summary Graph showing the rarity of the hostname “92n7au[.]uhabq9[.]com” on a customer network.](https://cdn.prod.website-files.com/626ff4d25aca2edf4325ff97/670d96b065612663d098df74_670d956f4dda5eb6ac9e650f_Screenshot%25202024-10-14%2520at%25203.04.22%25E2%2580%25AFPM.png)
![Screenshot of a Model Alert Event log showing a device connecting to the endpoint “is5jg[.]3zweuj[.]com” over port 32091.](https://cdn.prod.website-files.com/626ff4d25aca2edf4325ff97/670d96b065612663d098df7d_670d959854eb594420fdc971_Screenshot%25202024-10-14%2520at%25203.05.03%25E2%2580%25AFPM.png)
![Screenshot of a Model Alert Event Log showing the device posting the string “i8xps1” to the hostname “72zf6.rxqfd[.]com.](https://cdn.prod.website-files.com/626ff4d25aca2edf4325ff97/670d96b065612663d098df80_670d95c562c6e392c7dc3ba8_Screenshot%25202024-10-14%2520at%25203.05.49%25E2%2580%25AFPM.png)
![Screenshot of a Model Alert Event Log showing the device posting the string “sqyjyadwwq” to the hostname “9yrh7.mea5ms[.]com”.](https://cdn.prod.website-files.com/626ff4d25aca2edf4325ff97/670d96b065612663d098df7a_670d95e4b1dbad771717553c_Screenshot%25202024-10-14%2520at%25203.06.20%25E2%2580%25AFPM.png)
