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April 29, 2020

How Email Attackers Are Buying Domain Names to Get Inboxes

Explore how mass domain purchasing allows cyber-criminals to stay ahead of legacy email tools — and how cyber AI stops the threats that slip through.
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.
Written by
Dan Fein
VP, Product
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29
Apr 2020

It is by now common knowledge that the vast majority of cyber-threats start with an email. In the current working conditions, this is more true than ever – with a recent study reporting a 30,000% increase in phishing, websites, and malware targeting remote users.

Many email security tools struggle to detect threats they encounter for the first time. Attackers know this and are leveraging many techniques to take advantage of this fundamental flaw. This includes automation to mutate common threat variants, resulting in a massive increase in unknown threats. Another technique, which will be the focus of this blog post, is the rapid and widespread creation of new domains in order to evade reputation checks and signature-based detection.

The recent surge in domain creation

While traditional tools have to rely on identifying campaigns and patterns across multiple emails to establish whether or not an email is malicious, Cyber AI technology doesn’t require classifying emails into buckets in order to know they don’t belong. There is no need, therefore, to actively track campaigns. But as security researchers, it’s hard to miss some trends.

Since the coronavirus outbreak, we have seen the number of domains registered related to COVID-19 increase by 130,000. In this time, 60% of all spear phishing threats neutralized by Antigena Email were related to COVID-19 or remote work. Another recent study determined that 10,000 coronavirus-related domains are created every day, with roughly nine out of ten of these either malicious or attempting to generate sales of fake products.

With attackers also taking advantage of changing online behaviors arising from the pandemic, another trend we’ve seen is the proliferation of the keyword ‘Zoom’ in some of the unpopular domains that bypassed traditional tools, as attackers leverage the video conferencing platform’s recent rise in usage.

“I believe that hackers identified coronavirus as something users are desperate to find information on. Panic leads to irrational thinking and people forget the basics of cyber security.”

— COO, Atlas VPN

I recently wrote a blog post on the idea of ‘fearware’ and why it’s so successful. Right now, people are desperate for information, and attackers know this. Cyber-criminals play into fear, uncertainty, and doubt (FUD) through a number of mechanisms, and we have since seen a variety of imaginative attempts to engage recipients. These emails range from fake ‘virus trackers’, to sending emails purporting to be from Amazon, claiming an unmanageable rise in newly registered accounts, and demanding “re-registration” of the recipient’s credit card details should they wish to keep their account.

Domain name purchasing: A vicious cycle

Purchasing thousands of new domains and sending malicious emails en masse is a tried and tested technique that cyber-criminals have been leveraging for decades. Now with automation, they’re doing it faster than ever before.

Here’s why it works.

Traditional security tools work by analyzing emails in isolation, measuring them against static blacklists of ‘known bads’. By way of analogy, the gateway tool here is acting like a security guard standing at the perimeter of an organization’s physical premises, asking every individual who enters: “are you malicious?”

The binary answer to this sole question is extracted by looking at some metadata around the email, including the sender’s IP, their email address domain, and any embedded links or attachments. They analyze this data in a vacuum, and at face value, with no consideration towards the relationship between that data, the recipient, and the rest of the business. They run reputation checks, asking “have I seen this IP or domain before?” Crucially, if the answer is no, they let them straight through.

To spell that out, if the domain is brand new, it won’t have a reputation, and as these traditional tools have a limited ability to identify potential harmful elements via any other means, they have no choice but to let them in by default.

These methods barely scratch the surface of a much wider range of characteristics that a malicious email might contain. And as email threats get ever more sophisticated, the ‘innocent until proven guilty approach’ is not enough. For a comprehensive check, we would want to ask: does the domain have any previous relationship with the recipient? The organization as a whole? Does it look suspiciously visually similar to other domains? Is this the first time we’ve seen an inbound email from this user? Has anybody in the organization ever shared a link with this domain? Has any user ever visited this link?

Legacy tools are blatantly asking the wrong questions, to which attackers know the answers. And usually, they can skirt by these inattentive security guards by paying just a few pennies for new domains.

How to buy your way in

Let’s look at the situation from an attacker’s perspective. They just need one email to land and it could be keys to the kingdom, so an upfront purchase of a few thousand new domains will almost inevitably pay off. And they’d pay the price as long as it’s working and they’re profiting.

This is exactly what attackers are doing. Newly-registered domains consistently get through gateways until these traditional tools are armed with enough information to determine that the domains are bad, by which point thousands or even millions of emails could have been successfully delivered. As soon as the attack infrastructure is worn out, the attackers will abandon it, and very easily just purchase and deploy a new set of domains.

And so, the vicious cycle continues. Like a game of ‘whack-a-mole’, these legacy ‘solutions’ will continue to hammer down on recognized ‘bad’ emails – all the while more malicious domains are being created in the thousands in preparation for the next campaign. This is the ‘Domain Game’, and it’s a hard game for defenders to win.

Asking the right questions

Thankfully, the solution to this problem is as simple as the problem itself. It requires a movement away from the legacy approach and towards deploying technology that is up to par with the speed and scale of today’s attackers.

In the last two years, new technologies have emerged that leverage AI, seeking to understand the human behind the email address. Rather than inspecting incoming traffic at the surface-level and asking binary questions, this paradigm shift away from this insufficient legacy approach asks the right questions: not simply “are you malicious?”, but crucially: “do you belong?”

Informed by a nuanced understanding of the recipient, their peers, and the organization at large, every inbound, outbound, and internal email is analyzed in context, and is then re-analyzed over and over again in light of evolving evidence. Asking the right questions and understanding the human invariably sets a far higher standard for acceptable catch rates with unknown threats on first encounter. This approach far outpaces traditional email defenses which have proven to fail and leave companies and their employees vulnerable to malicious emails sitting in their inboxes.

Rather than desperately bashing away at blacklisted domains and IP addresses in an ill-fated attempt to beat the attackers, we can change the game altogether, tilting the scales in favor of the defenders – securing our inboxes and our organizations at large.

Learn more about Antigena Email.

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.
Written by
Dan Fein
VP, Product

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June 26, 2025

Patch and Persist: Darktrace’s Detection of Blind Eagle (APT-C-36)

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What is Blind Eagle?

Since 2018, APT-C-36, also known as Blind Eagle, has been observed performing cyber-attacks targeting various sectors across multiple countries in Latin America, with a particular focus on Colombian organizations.

Blind Eagle characteristically targets government institutions, financial organizations, and critical infrastructure [1][2].

Attacks carried out by Blind Eagle actors typically start with a phishing email and the group have been observed utilizing various Remote Access Trojans (RAT) variants, which often have in-built methods for hiding command-and-control (C2) traffic from detection [3].

What we know about Blind Eagle from a recent campaign

Since November 2024, Blind Eagle actors have been conducting an ongoing campaign targeting Colombian organizations [1].

In this campaign, threat actors have been observed using phishing emails to deliver malicious URL links to targeted recipients, similar to the way threat actors have previously been observed exploiting CVE-2024-43451, a vulnerability in Microsoft Windows that allows the disclosure of a user’s NTLMv2 password hash upon minimal interaction with a malicious file [4].

Despite Microsoft patching this vulnerability in November 2024 [1][4], Blind Eagle actors have continued to exploit the minimal interaction mechanism, though no longer with the intent of harvesting NTLMv2 password hashes. Instead, phishing emails are sent to targets containing a malicious URL which, when clicked, initiates the download of a malicious file. This file is then triggered by minimal user interaction.

Clicking on the file triggers a WebDAV request, with a connection being made over HTTP port 80 using the user agent ‘Microsoft-WebDAV-MiniRedir/10.0.19044’. WebDAV is a transmission protocol which allows files or complete directories to be made available through the internet, and to be transmitted to devices [5]. The next stage payload is then downloaded via another WebDAV request and malware is executed on the target device.

Attackers are notified when a recipient downloads the malicious files they send, providing an insight into potential targets [1].

Darktrace’s coverage of Blind Eagle

In late February 2025, Darktrace observed activity assessed with medium confidence to be  associated with Blind Eagle on the network of a customer in Colombia.

Within a period of just five hours, Darktrace / NETWORK detected a device being redirected through a rare external location, downloading multiple executable files, and ultimately exfiltrating data from the customer’s environment.

Since the customer did not have Darktrace’s Autonomous Response capability enabled on their network, no actions were taken to contain the compromise, allowing it to escalate until the customer’s security team responded to the alerts provided by Darktrace.

Darktrace observed a device on the customer’s network being directed over HTTP to a rare external IP, namely 62[.]60[.]226[.]112, which had never previously been seen in this customer’s environment and was geolocated in Germany. Multiple open-source intelligence (OSINT) providers have since linked this endpoint with phishing and malware campaigns [9].

The device then proceeded to download the executable file hxxp://62[.]60[.]226[.]112/file/3601_2042.exe.

Darktrace’s detection of the affected device connecting to an unusual location based in Germany.
Figure 1: Darktrace’s detection of the affected device connecting to an unusual location based in Germany.
Darktrace’s detection of the affected device downloading an executable file from the suspicious endpoint.
Figure 2: Darktrace’s detection of the affected device downloading an executable file from the suspicious endpoint.

The device was then observed making unusual connections to the rare endpoint 21ene.ip-ddns[.]com and performing unusual external data activity.

This dynamic DNS endpoint allows a device to access an endpoint using a domain name in place of a changing IP address. Dynamic DNS services ensure the DNS record of a domain name is automatically updated when the IP address changes. As such, malicious actors can use these services and endpoints to dynamically establish connections to C2 infrastructure [6].

Further investigation into this dynamic endpoint using OSINT revealed multiple associations with previous likely Blind Eagle compromises, as well as Remcos malware, a RAT commonly deployed via phishing campaigns [7][8][10].

Darktrace’s detection of the affected device connecting to the suspicious dynamic DNS endpoint, 21ene.ip-ddns[.]com.
Figure 3: Darktrace’s detection of the affected device connecting to the suspicious dynamic DNS endpoint, 21ene.ip-ddns[.]com.

Shortly after this, Darktrace observed the user agent ‘Microsoft-WebDAV-MiniRedir/10.0.19045’, indicating usage of the aforementioned transmission protocol WebDAV. The device was subsequently observed connected to an endpoint associated with Github and downloading data, suggesting that the device was retrieving a malicious tool or payload. The device then began to communicate to the malicious endpoint diciembrenotasenclub[.]longmusic[.]com over the new TCP port 1512 [11].

Around this time, the device was also observed uploading data to the endpoints 21ene.ip-ddns[.]com and diciembrenotasenclub[.]longmusic[.]com, with transfers of 60 MiB and 5.6 MiB observed respectively.

Figure 4: UI graph showing external data transfer activity.

This chain of activity triggered an Enhanced Monitoring model alert in Darktrace / NETWORK. These high-priority model alerts are designed to trigger in response to higher fidelity indicators of compromise (IoCs), suggesting that a device is performing activity consistent with a compromise.

 Darktrace’s detection of initial attack chain activity.
Figure 5: Darktrace’s detection of initial attack chain activity.

A second Enhanced Monitoring model was also triggered by this device following the download of the aforementioned executable file (hxxp://62[.]60[.]226[.]112/file/3601_2042.exe) and the observed increase in C2 activity.

Following this activity, Darktrace continued to observe the device beaconing to the 21ene.ip-ddns[.]com endpoint.

Darktrace’s Cyber AI Analyst was able to correlate each of the individual detections involved in this compromise, identifying them as part of a broader incident that encompassed C2 connectivity, suspicious downloads, and external data transfers.

Cyber AI Analyst’s investigation into the activity observed on the affected device.
Figure 6: Cyber AI Analyst’s investigation into the activity observed on the affected device.
Figure 7: Cyber AI Analyst’s detection of the affected device’s broader connectivity throughout the course of the attack.

As the affected customer did not have Darktrace’s Autonomous Response configured at the time, the attack was able to progress unabated. Had Darktrace been properly enabled, it would have been able to take a number of actions to halt the escalation of the attack.

For example, the unusual beaconing connections and the download of an unexpected file from an uncommon location would have been shut down by blocking the device from making external connections to the relevant destinations.

Conclusion

The persistence of Blind Eagle and ability to adapt its tactics, even after patches were released, and the speed at which the group were able to continue using pre-established TTPs highlights that timely vulnerability management and patch application, while essential, is not a standalone defense.

Organizations must adopt security solutions that use anomaly-based detection to identify emerging and adapting threats by recognizing deviations in user or device behavior that may indicate malicious activity. Complementing this with an autonomous decision maker that can identify, connect, and contain compromise-like activity is crucial for safeguarding organizational networks against constantly evolving and sophisticated threat actors.

Credit to Charlotte Thompson (Senior Cyber Analyst), Eugene Chua (Principal Cyber Analyst) and Ryan Traill (Analyst Content Lead)

Appendices

IoCs

IoC – Type - Confidence
Microsoft-WebDAV-MiniRedir/10.0.19045 – User Agent

62[.]60[.]226[.]112 – IP – Medium Confidence

hxxp://62[.]60[.]226[.]112/file/3601_2042.exe – Payload Download – Medium Confidence

21ene.ip-ddns[.]com – Dynamic DNS Endpoint – Medium Confidence

diciembrenotasenclub[.]longmusic[.]com  - Hostname – Medium Confidence

Darktrace’s model alert coverage

Anomalous File / Suspicious HTTP Redirect
Anomalous File / EXE from Rare External Location
Anomalous File / Multiple EXE from Rare External Location
Anomalous Server Activity / Outgoing from Server
Unusual Activity / Unusual External Data to New Endpoint
Device / Anomalous Github Download
Anomalous Connection / Multiple Connections to New External TCP Port
Device / Initial Attack Chain Activity
Anomalous Server Activity / Rare External from Server
Compromise / Suspicious File and C2
Compromise / Fast Beaconing to DGA
Compromise / Large Number of Suspicious Failed Connections
Device / Large Number of Model Alert

Mitre Attack Mapping:

Tactic – Technique – Technique Name

Initial Access - T1189 – Drive-by Compromise
Initial Access - T1190 – Exploit Public-Facing Application
Initial Access ICS - T0862 – Supply Chain Compromise
Initial Access ICS - T0865 – Spearphishing Attachment
Initial Access ICS - T0817 - Drive-by Compromise
Resource Development - T1588.001 – Malware
Lateral Movement ICS - T0843 – Program Download
Command and Control - T1105 - Ingress Tool Transfer
Command and Control - T1095 – Non-Application Layer Protocol
Command and Control - T1571 – Non-Standard Port
Command and Control - T1568.002 – Domain Generation Algorithms
Command and Control ICS - T0869 – Standard Application Layer Protocol
Evasion ICS - T0849 – Masquerading
Exfiltration - T1041 – Exfiltration Over C2 Channel
Exfiltration - T1567.002 – Exfiltration to Cloud Storage

References

1)    https://research.checkpoint.com/2025/blind-eagle-and-justice-for-all/

2)    https://assets.kpmg.com/content/dam/kpmgsites/in/pdf/2025/04/kpmg-ctip-blind-eagle-01-apr-2025.pdf.coredownload.inline.pdf

3)    https://www.checkpoint.com/cyber-hub/threat-prevention/what-is-remote-access-trojan/#:~:text=They%20might%20be%20attached%20to,remote%20access%20or%20system%20administration

4)    https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-43451

5)    https://www.ionos.co.uk/digitalguide/server/know-how/webdav/

6)    https://vercara.digicert.com/resources/dynamic-dns-resolution-as-an-obfuscation-technique

7)    https://threatfox.abuse.ch/ioc/1437795

8)    https://www.checkpoint.com/cyber-hub/threat-prevention/what-is-malware/remcos-malware/

9)    https://www.virustotal.com/gui/url/b3189db6ddc578005cb6986f86e9680e7f71fe69f87f9498fa77ed7b1285e268

10) https://www.virustotal.com/gui/domain/21ene.ip-ddns.com

11) https://www.virustotal.com/gui/domain/diciembrenotasenclub.longmusic.com/community

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Charlotte Thompson
Cyber Analyst

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June 18, 2025

Darktrace Collaborates with Microsoft: Unifying Email Security with a Shared Vision

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In today’s threat landscape, email remains the most targeted vector for cyberattacks. Organizations require not only multi-layered defenses but also advanced, integrated systems that work collaboratively to proactively mitigate threats before they cause damage

That’s why we’re proud to announce a new integration between Darktrace / EMAIL and Microsoft Defender for Office 365, delivering a Unified Quarantine experience that empowers security teams with seamless visibility, control, and response across both platforms.

This announcement builds on a strong and growing collaboration. In 2024, Darktrace was honored as Microsoft UK Partner of the Year and recognized as a Security Trailblazer at the annual Microsoft Security 20/20 Awards, a testament to our shared commitment to innovation and customer-centric security.

A Shared Mission: Stopping Threats at Machine Speed

This integration is more than a technical milestone,as it’s a reflection of a shared mission: to protect organizations from both known and unknown threats, with efficiency, accuracy, and transparency.

  • Microsoft Defender for Office 365 delivers a comprehensive security framework that safeguards Microsoft 365 email and collaboration workloads leveraging advanced AI, global threat intelligence and information on known attack infrastructure.
  • Darktrace / EMAIL complements this with Self-Learning AI that understands the unique communication patterns within each organization, detecting subtle anomalies that evade traditional detection methods.

Together, we’re delivering multi-layered, adaptive protection that’s greater than the sum of its parts.

“Our integration with Microsoft gives security teams the tools they need to act faster and more precisely to detect and respond to threats,” said Jill Popelka, CEO of Darktrace. “Together, we’re strengthening defenses where it matters most to our customers: at the inbox.”

Unified Quarantine: One View, Total Clarity

The new Unified Quarantine experience gives customers a single pane of glass to view and manage email threatsregardless of which product took action. This means:

  • Faster investigations with consolidated visibility
  • Clear attribution of actions and outcomes across both platforms
  • Streamlined workflows for security teams managing complex environments

“This integration is a testament to the power of combining Microsoft’s global threat intelligence with Darktrace’s unique ability to understand the ‘self’ of an organization,” said Jack Stockdale, CTO of Darktrace. “Together, we’re delivering a new standard in proactive, adaptive email security.”

A New Era of Collaborative Cyber Defense

This collaboration represents a broader shift in cybersecurity: from siloed tools to integrated ecosystems. As attackers become more sophisticated, defenders must move faster, smarter, and in unison.

Through this integration, Darktrace and Microsoft establish a new standard for collaboration between native and third-party security solutions, enhancing not only threat detection but also comprehensive understanding and proactive measures against threats.

We’re excited to bring this innovation to our customers and continue building a future where AI and human expertise collaborate to secure the enterprise.

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About the author
Carlos Gray
Senior Product Marketing Manager, Email
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