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Ransomware

Inside the SOC

The early signs of ransomware: A blitz game

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06
Sep 2021
06
Sep 2021
When it comes to tackling the problem of ransomware, attack is the best form of defense. This blog explores how to spot the early indicators of ransomware, which can prove a pivotal advantage as the game develops.

The deployment of ransomware is the endgame of a cyber-attack. A threat actor must have accomplished several previous steps – including lateral movement and privilege escalation – to reach this final position. The ability to detect and counter the early moves is therefore just as important as detecting the encryption itself.

Attackers are using diverse strategies – such as ‘Living off the Land’ and carefully crafting their command and control (C2) – to blend in with normal network traffic and evade traditional security defenses. The analysis below examines the Tactics, Techniques and Procedures (TTPs) used by many ransomware actors by unpacking a compromise which occurred at a defense contractor in Canada.

Phases of a ransomware attack

Figure 1: Timeline of the attack.

The opening: Initial access to privileged account

The first indicator of compromise was a login on a server with an unusual credential, followed by unusual admin activity. The attacker may have gained access to the username and password in a number of ways, from credential stuffing to buying them on the Dark Web. As the attacker had privileged access from the get-go, there was no need for privilege escalation.

Lateral movement

Two days later, the attacker began to spread from the initial server. The compromised server began to send out unusual Windows Management Instrumentation (WMI) commands.

It began remotely controlling four other devices – authenticating on them with a single admin credential. One of the destinations was a domain controller (DC), another was a backup server.

By using WMI – a common admin tool – for lateral movement, the attacker opted to ‘live off the land’ rather than introduce a new lateral movement tool, aiming to remain unnoticed by the company’s security stack. The unusual use of WMI was picked up by Darktrace and the timings of the unusual WMI connections were pieced together by Cyber AI Analyst.

Models:

  • New or Uncommon WMI Activity
  • AI Analyst / Extensive Chain of Administrative Connections

Establish C2

The four devices then connected to the IP 185.250.151[.]172. Three of them, including the DC and backup server, established SSL beacons to the IP using the dynamic DNS domain goog1e.ezua[.]com.

The C2 endpoints had very little open-source intelligence (OSINT) available, but it seems that a Cobalt Strike-style script had used the endpoint in the past. This suggests complex tooling, as the attacker used dynamic SSL and spoofed Google to mask their beaconing.

Interestingly, through the entirety of the attack, only these three devices used SSL connections for beaconing, while later C2 occurred over unencrypted protocols. It appears these three critical devices were treated differently to the other infected devices on the network.

Models:

  • Immediate breach of Anomalous External Activity from Critical Network Device, then several model breaches involving beaconing and SSL to dynamic DNS. (Domain Controller DynDNS SSL or HTTP was particularly specific to this activity.)

The middle game: Internal reconnaissance and further lateral movement

The attack chain took the form of two cycles of lateral movement, followed by establishing C2 at the newly controlled destinations.

Figure 2: Observed chain of lateral movement and C2.

So, after establishing C2, the DC made WMI requests to 20 further IPs over an extended period. It also scanned 234 IPs via ICMP pings, presumably in an attempt to find more hosts.

Many of these were eventually found with ransom notes, in particular when the targeted devices were hypervisors. The ransomware was likely deployed with remote commands via WMI.

Models:

  • AI Analyst / Suspicious Chain of Administrative Connections (from the initial server to the DC to the hypervisor)
  • AI Analyst / Extensive Suspicious WMI Activity (from the DC)
  • Device / ICMP Address Scan, Scanning of Multiple Devices AI Analyst incident (from the DC)

Further C2

As the second stage of lateral movement stopped, a second stage of unencrypted C2 was seen from five new devices. Each started with GET requests to the IP seen in the SSL C2 (185.250.151[.]172), which used the spoofed hostname google[.]com.

Activity started on each device with HTTP requests for a URI ending in .png, before a more consistent beaconing to the URI /books/. Eventually, the devices made POST requests to the URI /ebooks/?k= (a unique identifier for each device). All this appears to be a way of concealing a C2 beacon in what looks like plausible traffic to Google.

In this way, by encrypting some C2 connections with SSL to a Dynamic DNS domain, while crafting other unencrypted HTTP to look like traffic to google[.]com, the attacker managed to operate undetected by the company’s antivirus tools.

Darktrace identified this anomalous activity and generated a large number of external connectivity model breaches.

Models:

  • Eight breaches of Compromise / HTTP Beaconing to New Endpoint from the affected devices

Accomplish mission: Checkmate

Finally, the attacker deployed ransomware. In the ransom note, they stated that sensitive information had been exfiltrated and would be leaked if the company did not pay.

However, this was a lie. Darktrace confirmed that no data had been exfiltrated, as the C2 communications had sent far too little data. Lying about data exfiltration in order to extort a ransom is a common tactic for attackers, and visibility is crucial to determine whether a threat actor is bluffing.

In addition, Antigena – Darktrace’s Autonomous Response technology – blocked an internal download from one of the servers compromised in the first round of lateral movement, because it was an unusual incoming data volume for the client device. This was most likely the attacker attempting to transfer data in preparation for the end goal, so the block may have prevented this data from being moved for exfiltration.

Figure 3: Antigena model breach.

Figure 4: Device is blocked from SMB communication with the compromised server three seconds later.

Models:

  • Unusual Incoming Data Volume
  • High Volume Server Data Transfer

Unfortunately, Antigena was not active on the majority of the devices involved in the incident. If in active mode, Antigena would have stopped the early stages of this activity, including the unusual administrative logins and beaconing. The customer is now working to fully configure Antigena, so they benefit from 24/7 Autonomous Response.

Cyber AI Analyst investigates

Darktrace’s AI spotted and reported on beaconing from several devices including the DC, which was the highest scoring device for unusual behavior at the time of the activity. It condensed this information into three incidents – ‘Possible SSL Command and Control’, ‘Extensive Suspicious Remote WMI Activity’, and ‘Scanning of Remote Devices’.

Crucially, Cyber AI Analyst not only summarized the admin activity from the DC but also linked it back to the first device through an unusual chain of administrative connections.

Figure 5: Cyber AI Analyst incident showing a suspicious chain of administrative connections linking the first device in the chain of connections to a hypervisor where a ransom note was found via the compromised DC, saving valuable time in the investigation. It also highlights the credential common to all of the lateral movement connections.

Finding lateral movement chains manually is a laborious process well suited to AI. In this case, it enabled the security team to quickly trace back to the device which was the likely source of the attack and find the common credential in the connections.

Play the game like a machine

To get the full picture of a ransomware attack, it is important to look beyond the final encryption to previous phases of the kill chain. In the attack above, the encryption itself did not generate network traffic, so detecting the intrusion at its early stages was vital.

Despite the attacker ‘Living off the Land’ and using WMI with a compromised admin credential, as well as spoofing the common hostname google[.]com for C2 and applying dynamic DNS for SSL connections, Darktrace was able to identify all the stages of the attack and immediately piece them together into a meaningful security narrative. This would have been almost impossible for a human analyst to achieve without labor-intensive checking of the timings of individual connections.

With ransomware infections becoming faster and more frequent, with the threat of offensive AI looming closer and the Dark Web marketplace thriving, with security teams drowning under false positives and no time left on the clock, AI is now an essential part of any security solution. The board is set, the time is ticking, the stakes are higher than ever. Your move.

Thanks to Darktrace analyst Daniel Gentle for his insights on the above threat find.

IoCs:

IoCComment185.250.151[.]172IP address used for both HTTP and SSL C2goog1e.ezua[.]comDynamic DNS Hostname used for SSL C2

Darktrace model detections:

  • AI Analyst models:
  • Extensive Suspicious WMI Activity
  • Suspicious Chain of Administrative Connections
  • Scanning of Multiple Devices
  • Possible SSL Command and Control
  • Meta model:
  • Device / Large Number of model breaches
  • External connectivity models:
  • Anonymous Server Activity / Domain Controller DynDNS SSL or HTTP
  • Compromise / Suspicious TLS Beaconing to Rare External
  • Compromise / Beaconing Activity To External Rare
  • Compromise / SSL to DynDNS
  • Anomalous Server Activity / External Activity from Critical Network Device
  • Compromise / Sustained SSL or HTTP Increase
  • Compromise / Suspicious Beaconing Behaviour
  • Compromise / HTTP Beaconing to New Endpoint
  • Internal activity models:
  • Device / New or Uncommon WMI Activity
  • User / New Admin Credentials on Client
  • Device / ICMP Address Scan
  • Anomalous Connection / Unusual Incoming Data Volume
  • Unusual Activity / High Volume Server Data Transfer

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
ABOUT ThE AUTHOR
Brianna Leddy
Director of Analysis

Based in San Francisco, Brianna is Director of Analysis at Darktrace. She joined the analyst team in 2016 and has since advised a wide range of enterprise customers on advanced threat hunting and leveraging Self-Learning AI for detection and response. Brianna works closely with the Darktrace SOC team to proactively alert customers to emerging threats and investigate unusual behavior in enterprise environments. Brianna holds a Bachelor’s degree in Chemical Engineering from Carnegie Mellon University.

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Email

Looking Beyond Secure Email Gateways with the Latest Innovations to Darktrace/Email

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09
Apr 2024

Organizations Should Demand More from their Email Security

In response to a more intricate threat landscape, organizations should view email security as a critical component of their defense-in-depth strategy, rather than defending the inbox alone with a traditional Secure Email Gateway (SEG). Organizations need more than a traditional gateway – that doubles, instead of replaces, the capabilities provided by native security vendor – and require an equally granular degree of analysis across all messaging, including inbound, outbound, and lateral mail, plus Teams messages.  

Darktrace/Email is the industry’s most advanced cloud email security, powered by Self-Learning AI. It combines AI techniques to exceed the accuracy and efficiency of leading security solutions, and is the only security built to elevate, not duplicate, native email security.  

With its largest update ever, Darktrace/Email introduces the following innovations, finally allowing security teams to look beyond secure email gateways with autonomous AI:

  • AI-augmented data loss prevention to stop the entire spectrum of outbound mail threats
  • an easy way to deploy DMARC quickly with AI
  • major enhancements to streamline SOC workflows and increase the detection of sophisticated phishing links
  • expansion of Darktrace’s leading AI prevention to lateral mail, account compromise and Microsoft Teams

What’s New with Darktrace/Email  

Data Loss Prevention  

Block the entire spectrum of outbound mail threats with advanced data loss prevention that builds on tags in native email to stop unknown, accidental, and malicious data loss

Darktrace understands normal at individual user, group and organization level with a proven AI that detects abnormal user behavior and dynamic content changes. Using this understanding, Darktrace/Email actions outbound emails to stop unknown, accidental and malicious data loss.  

Traditional DLP solutions only take into account classified data, which relies on the manual input of labelling each data piece, or creating rules to catch pattern matches that try to stop data of certain types leaving the organization. But in today’s world of constantly changing data, regular expression and fingerprinting detection are no longer enough.

  • Human error – Because it understands normal for every user, Darktrace/Email can recognize cases of misdirected emails. Even if the data is correctly labelled or insensitive, Darktrace recognizes when the context in which it is being sent could be a case of data loss and warns the user.  
  • Unclassified data – Whereas traditional DLP solutions can only take action on classified data, Darktrace analyzes the range of data that is either pending labels or can’t be labeled with typical capabilities due to its understanding of the content and context of every email.  
  • Insider threat – If a malicious actor has compromised an account, data exfiltration may still be attempted on encrypted, intellectual property, or other forms of unlabelled data to avoid detection. Darktrace analyses user behaviour to catch cases of unusual data exfiltration from individual accounts.

And classification efforts already in place aren’t wasted – Darktrace/Email extends Microsoft Purview policies and sensitivity labels to avoid duplicate workflows for the security team, combining the best of both approaches to ensure organizations maintain control and visibility over their data.

End User and Security Workflows

Achieve more than 60% improvement in the quality of end-user phishing reports and detection of sophisticated malicious weblinks1

Darktrace/Email improves end-user reporting from the ground up to save security team resource. Employees will always be on the front line of email security – while other solutions assume that end-user reporting is automatically of poor quality, Darktrace prioritizes improving users’ security awareness to increase the quality of end-user reporting from day one.  

Users are empowered to assess and report suspicious activity with contextual banners and Cyber AI Analyst generated narratives for potentially suspicious emails, resulting in 60% fewer benign emails reported.  

Out of the higher-quality emails that end up being reported, the next step is to reduce the amount of emails that reach the SOC. Darktrace/Email’s Mailbox Security Assistant automates their triage with secondary analysis combining additional behavioral signals – using x20 more metrics than previously – with advanced link analysis to detect 70% more sophisticated malicious phishing links.2 This directly alleviates the burden of manual triage for security analysts.

For the emails that are received by the SOC, Darktrace/Email uses automation to reduce time spent investigating per incident. With live inbox view, security teams gain access to a centralized platform that combines intuitive search capabilities, Cyber AI Analyst reports, and mobile application access. Analysts can take remediation actions from within Darktrace/Email, eliminating console hopping and accelerating incident response.

Darktrace takes a user-focused and business-centric approach to email security, in contrast to the attack-centric rules and signatures approach of secure email gateways

Microsoft Teams

Detect threats within your Teams environment such as account compromise, phishing, malware and data loss

Around 83% of Fortune 500 companies rely on Microsoft Office products and services, particularly Teams and SharePoint.3

Darktrace now leverages the same behavioral AI techniques for Microsoft customers across 365 and Teams, allowing organizations to detect threats and signals of account compromise within their Teams environment including social engineering, malware and data loss.  

The primary use case for Microsoft Teams protection is as a potential entry vector. While messaging has traditionally been internal only, as organizations open up it is becoming an entry vector which needs to be treated with the same level of caution as email. That’s why we’re bringing our proven AI approach to Microsoft Teams, that understands the user behind the message.  

Anomalous messaging behavior is also a highly relevant indicator of whether a user has been compromised. Unlike other solutions that analyze Microsoft Teams content which focus on payloads, Darktrace goes beyond basic link and sandbox analysis and looks at actual user behavior from both a content and context perspective. This linguistic understanding isn’t bound by the requirement to match a signature to a malicious payload, rather it looks at the context in which the message has been delivered. From this analysis, Darktrace can spot the early symptoms of account compromise such as early-stage social engineering before a payload is delivered.

Lateral Mail Analysis

Detect and respond to internal mailflow with multi-layered AI to prevent account takeover, lateral phishing and data leaks

The industry’s most robust account takeover protection now prevents lateral mail account compromise. Darktrace has always looked at internal mail to inform inbound and outbound decisions, but will now elevate suspicious lateral mail behaviour using the same AI techniques for inbound, outbound and Teams analysis.

Darktrace integrates signals from across the entire mailflow and communication patterns to determine symptoms of account compromise, now including lateral mailflow

Unlike other solutions which only analyze payloads, Darktrace analyzes a whole range of signals to catch lateral movement before a payload is delivered. Contributing yet another layer to the AI behavioral profile for each user, security teams can now use signals from lateral mail to spot the early symptoms of account takeover and take autonomous actions to prevent further compromise.

DMARC

Gain in-depth visibility and control of 3rd parties using your domain with an industry-first AI-assisted DMARC

Darktrace has created the easiest path to brand protection and compliance with the new Darktrace/DMARC. This new capability continuously stops spoofing and phishing from the enterprise domain, while automatically enhancing email security and reducing the attack surface.

Darktrace/DMARC helps to upskill businesses by providing step by step guidance and automated record suggestions provide a clear, efficient road to enforcement. It allows organizations to quickly achieve compliance with requirements from Google, Yahoo, and others, to ensure that their emails are reaching mailboxes.  

Meanwhile, Darktrace/DMARC helps to reduce the overall attack surface by providing visibility over shadow-IT and third-party vendors sending on behalf of an organization’s brand, while informing recipients when emails from their domains are sent from un-authenticated DMARC source.

Darktrace/DMARC integrates with the wider Darktrace product platform, sharing insights to help further secure your business across Email Attack Path and Attack Surface management.

Conclusion

To learn more about the new innovations to Darktrace/Email download the solution brief here.

All of the new updates to Darktrace/Email sit within the new Darktrace ActiveAI Security Platform, creating a feedback loop between email security and the rest of the digital estate for better protection. Click to read more about the Darktrace ActiveAI Security Platform or to hear about the latest innovations to Darktrace/OT, the most comprehensive prevention, detection, and response solution purpose built for critical infrastructures.  

Learn about the intersection of cyber and AI by downloading the State of AI Cyber Security 2024 report to discover global findings that may surprise you, insights from security leaders, and recommendations for addressing today’s top challenges that you may face, too.

References

[1] Internal Darktrace Research

[2] Internal Darktrace Research

[3] Essential Microsoft Office Statistics in 2024

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About the author
Carlos Gray
Product Manager

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Managing Risk Beyond CVE Scores With the Latest Innovations to Darktrace/OT

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09
Apr 2024

Identifying Cyber Risk in Industrial Organizations

Compromised OT devices in ICS and SCADA environments pose significant physical risks, even endangering lives. However, identifying CVEs in the multitude of complex OT devices is labor-intensive and time-consuming, draining valuable resources.

Even after identifying a vulnerability, implementing a patch presents its own challenges limited maintenance windows and the need for uninterrupted operations strain IT and OT teams often leading organizations to prioritize availability over security leading vulnerabilities remaining unresolved for over 5 years on average. (1)

Darktrace’s New Innovation

Darktrace is an industry leader in cybersecurity with 10+ years of experience securing OT environments where we take a fundamentally different approach using Self-Learning AI to enhance threat detection and response.

Continuing to combat the expanding threat landscape, Darktrace is excited to announce new capabilities that enable a contextualized and proactive approach to managing cyber risk at industrial organizations.

Today we launch an innovation to our OT Cybersecurity solution, Darktrace/OT, that will add a layer of proactivity, enabling a comprehensive approach to risk management. This industry leading innovation for Darktrace/OT moves beyond CVE scores to redefine vulnerability management for critical infrastructure, tackling the full breadth of risks not limited by traditional controls.  

Darktrace/OT is the only OT security solution with comprehensive Risk Management which includes:

  • Contextualized risk analysis unique to your organization
  • The most realistic evaluation and prioritization of OT risk
  • Effectively mitigate risk across your OT infrastructure, with and without patching.
  • The only OT security solution that evaluates your defenses against Advanced Persistent Threat (APT) Groups.

The most comprehensive prevention, detection, and response solution purpose built for Critical Infrastructures

Darktrace’s Self-Learning AI technology is a cutting-edge innovation that implements real time prevention, detection, response, and recovery for operational technologies and enables a fundamental shift from the traditional approach to cyber defense by learning a ‘pattern of life’ for every network, device, and user.  

Rather than relying on knowledge of past attacks, AI technology learns what is ‘normal’ for its environment, discovering previously unknown threats by detecting subtle shifts in behavior. Through identifying these unexpected anomalies, security teams can investigate novel attacks, discover blind spots, have live time visibility across all their physical and digital assets, and reduce time to detect, respond to, and triage security events.  

  • Achieve greater visibility of OT and IT devices across all levels of the Purdue Model.
  • The industry's only OT security to scale threat detection and response, with a 92% time saving from triage to recovery.  
  • The only OT focused security solution to provide bespoke Risk Management.

To learn more about how Darktrace/OT approaches unique use cases for industrial organizations visit the Darktrace/OT Webpage or join us LIVE at a city near you.

Read more below to discover how new innovations to Darktrace/OT are bringing a new, contextualized approach to Risk Management for Industrial organizations.

For more information on the entire Darktrace/OT Solution read our solution brief here.

Darktrace/OT and New Risk Management

Risk Identification

Leveraging the visibility of Darktrace/OT which identifies individual systems throughout the Purdue Model and the relationship between them, Darktrace/OT identifies high-risk CVEs and presents potential attack routes that go beyond techniques requiring a known exploit, such as misuse of legitimate services. Each attack path will have a mathematical evaluation of difficulty and impact from initial access to the high value objectives.  

Together this gives comprehensive coverage over your real and potential risks from both an attacker and known vulnerability perspectives. OT attack paths as seen here even leverage insights between the industrial and corporate communications to reveal ways threat actors may take advantage of IT-OT convergence. This revelation of imperceptible risks fills gaps in traditional risk analysis like remote access and insider threats.

Figure 1: Darktrace/OT visualizing the most critical attack paths at an organization
Figure 1: Darktrace/OT visualizing the most critical attack paths at an organization
Figure 2: A specific Attack Path identified by Darktrace/OT

Risk Prioritization

Darktrace/OT prioritizes remediations and mitigations based on difficulty and damage to your unique organization, using the established Attack Paths.

We ascertain the priorities that apply to your organization beyond pure theoretical damage answering questions like:

  • How difficult is a particular vulnerability to exploit considering the steps an attacker would require to reach it?
  • And, how significant would the impact be if it was exploited within this particular network?

This expanded approach to risk prioritization has a much more comprehensive evaluation of your organization's unique risk than has ever been possible before. Traditional approaches of ranking only known vulnerabilities with isolated scores using CVSS and exploitability metrics, often leaves gaps in IT-OT risks and is blind to legitimate service exploitation.

Figure 3: Darktrace/OT leverages its contextual understand of the organization’s network to prioritize remediation that will have the positive impact on the risk score

Darktrace provides mitigation strategies associated with each identified risk and the relevant impact it has on your overall risk posture, across all MITRE ATT&CK techniques.

What sets Darktrace apart is our ability to contextualize these mitigations within the broader business. When patching vulnerabilities directly isn’t possible, Darktrace identifies alternative actions that harden attack paths leading to critical assets. Hardening the surrounding attack path increases the difficulty and therefore reduces the likelihood and impact of a breach.

That means unpatched vulnerabilities and vulnerable devices aren’t left unprotected. This also has an added bonus, those hardening techniques work for all devices in that network segment, so apply one change, secure many.

Figure 4: Darktrace prioritizes mitigation reducing accessibility of vulnerability and the overall risk score when patches aren’t available

Communicate Board Level Risk with APT Threat Mapping

Darktrace/OT bridges theory and practice as the only security solution that maps MITRE techniques, frequently used by APT Groups, onto AI-assessed critical Attack Paths. This unique solution provides unparalleled insights including sector and location intelligence, possible operating platforms, common techniques, exploited CVEs, and the number of potential devices affected in your environment, supporting holistic risk assessment and proactive defense measures.

Ultimately, this becomes a power dashboard to communicate board level risk, using both metric based evidence and industry standard threat mapping.

Conclusion

Darktrace/OT is part of the Darktrace ActiveAI Security Platform a native, holistic, AI-driven platform built on over ten years of AI research. It helps security teams shift to more a productive mode, finding the known and the unknown attacks and transforming the SOC with the various Darktrace products to drive efficiency gains. It does this across the whole incident lifecycle to lower risk, reduce time spent on active incidents, and drive return on investment.

Discover more about Darktrace's ever-strengthening platform with the upcoming changes coming to our Darktrace/Email product and other launch day blogs.

Join Darktrace LIVE half-day event to understand the reality versus the hype surrounding AI and how to achieve cyber resilience.

Learn about the intersection of cyber and AI by downloading the State of AI Cyber Security 2024 report to discover global findings that may surprise you, insights from security leaders, and recommendations for addressing today’s top challenges that you may face, too.  

References

1. https://research-information.bris.ac.uk/ws/portalfiles/portal/313646831/Catch_Me_if_You_Can.pdf

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About the author
Mitchell Bezzina
VP, Product and Solutions Marketing
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