Cyber-criminals target weekends and holidays to strike while employees are away. Discover how defensive AI can protect your business 24/7.
Ransomware: An unwanted present
Darktrace regularly observes an increase in cyber-attacks carried out during holidays, weekends, and outside of working hours. It is clear that such ‘off peak’ attacks allow easy exploitation of standard organizational practices and human vulnerabilities.
As reduced staff wind down and employees mentally and physically log off from the workplace, there is a decline in the speed of detection and triage within an enterprise. This allows threat actors to sneak in unnoticed. Without real-time autonomous systems, when executed these unexpected attacks have a much greater impact on response and recovery.
One of the most frequent threats detected out of hours is ransomware. In 76% of infections, the encryption process begins either after hours or during the weekend. Darktrace was alerted to a ransomware incident which was executed in the early hours of a client’s network on Christmas Day, when most employees were offline.
Figure 1: Timeline of the Christmas Day ransomware breach
Over a week before the encryption began, an initial foothold was established on an unassuming desktop. Using this vector, the threat actor was able to move laterally and gain access to two domain controllers – servers used to verify users and authenticate requests. The two servers then made unusual command and control (C2) connections to a rare endpoint linked to ransomware. Next, the threat went into hiding. Although Darktrace had alerted to this activity at every stage, the security team was under great stress during the December period and did not manage to action even these highly critical alerts. Without Darktrace / NETWORK or Proactive Threat Notifications (PTNs), the threat remained uninterrupted.
It suddenly re-emerged after hours on December 24 and utilized its additional privileges to write suspicious executable files to a range of internal devices. A pre-determined set of company data was exfiltrated and a ransomware payload downloaded from the same cloud destination.
A cyber-attack striking on a public holiday is likely to destabilize communication – who is responsible for dealing with it? Are they hard to reach? Are there different protocols for an out-of-hours breach? When unexpected during the holidays, these questions may be surprisingly hard to answer. When answers finally arrive, it is often too late – the damage has already been done.
Once dealt with, there are also repercussions for evaluation: security personnel will be needed to investigate what happened and the future consequences of the attack. If internal staff are hard to mobilize, and external security services come at a premium, this process can be arduous and key evidence may be lost. In turn, the company will be left open to similar attacks in the future.
Saturday night fearware
Holidays clearly pose a human and logistical vulnerability. However, it is often overlooked that these same down periods occur on a small scale throughout the year – at the end of every week. Darktrace has observed a huge surge in weekend attacks in recent months.
Figure 2: Diagram of the key terms Darktrace has observed over the past six months in out-of-hours model breaches
This includes another ransomware incident, which struck a hospitality organization based in the UK. A company device was compromised when a user unintentionally accessed a harmful email. The infection exploited cleartext password files to laterally move to four other devices, including critical servers which it then used to host outbound spam and further disseminate. For several following weekends, compromised devices made a large volume of open or Tor-hosted C2 connections to endpoints associated with the XINOF ransomware.
This example shows that out-of-hours infections can come from any vector, and human compliance errors can be exploited to quickly propagate malware and hide before the security team returns to work on Monday. With many data breaches already taking months to discover, threat actors are looking to extend their concealment by implementing the initial compromise at times with decreased monitoring.
Improving detection of these first compromises and adapting to smaller out-of-hours periods may lead to improved response and adjustment for larger holidays as well. But for a permanent fix, enterprises need a proactive approach.
The solution which never sleeps
In the case study above, Autonomous Response was possible at every attack stage, had it been switched on in active mode. Darktrace / EMAIL would have stopped the initial compromise by identifying the anomalous attachment and quarantining the infection before it could enter the network. Once inside, the critical servers exploited would not have been compromised, as the malicious login activity using gathered passwords would have been halted until verified. Finally, connections to the malicious sites containing the XINOF payload could have been blocked, stopping further damages from occurring.
Unlike a human, AI never sleeps, and never takes a holiday. Instead, the AI stays active around the clock, containing all types of threats in their earliest stages. This prevents malicious activity from escalating while giving human security teams valuable airtime to react and remediate the root cause of any incidents.
If a security team requires an extra set of eyes to augment their investigation, incidents can also be mitigated with Proactive Threat Notifications (PTNs). This service funnels high-severity detections straight into Darktrace’s customer-dedicated SOC to be investigated by expert cyber analysts. The Darktrace PTN SOC has a follow-the-sun approach to monitoring customer environments, meaning that organizations are protected from attacks around the clock.
Timing is everything
The case studies in this blog should serve as a reminder of the need for 24/7 attentiveness. As security professionals increase their skills and creativity in combating threats, malicious actors continue to adapt themselves and are using timing to their advantage during attacks. Now more than ever, it is clear that autonomous AI-based detection is the only means to remove the advantage of timing from threat actors so that even when the office is closed or the laptop is switched off, your security remains on.
Thanks to Darktrace Product Manager Gabriel Few-Wiegratz for his insights.
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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.
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)
