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July 25, 2021

Detecting Lateral Movement in Crypto-Botnets

Explore how crypto botnets move laterally within networks and the implications for cybersecurity and threat detection.
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
Max Heinemeyer
Global Field CISO
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25
Jul 2021

Botnets have increasingly become the vehicle of choice to deliver crypto-mining malware. By infecting various corporate assets such as servers and IoT devices, cyber-criminals can use the collective processing power of hundreds – or thousands – of machines to mine cryptocurrency and spread to further devices.

This blog explores how an Internet-facing server was breached in a company in Singapore. The threat actors used the device to move laterally and deploy crypto-mining software. Within two days, several devices in the company had begun cryptocurrency mining.

Creating the botnet

Only a few days after Darktrace had been installed in a Proof of Value (POV) trial, it detected a server in the company downloading a malicious executable from a rare endpoint, 167.71.87[.]85.

Figure 1: Timeline of the attack.

The server was observed making HTTP connections to a range of rare external endpoints, without a user agent header. The main hostname was t[.]amynx[.]com, a domain on open-source intelligence (OSINT) associated with crypto-mining trojans.

The device initiated repeated external connections to a range of external IPs over the TCP port 445 (SMB). This was followed by an unusually large number of internal connection attempts to a wide range of devices, suggesting scanning activity.

Figure 2: Details for the TCP scanning activity in a similar incident — note the consolidation of six relevant events into one summary.

Growing the botnet

The malware began to move laterally from the initially infected server, predominantly by establishing chains of unsual RDP connections. Subsequently, the server started making external SMB and RPC connections to rare endpoints on the Internet, in an attempt to find further vulnerable hosts.

Other lateral movement activities included the repeated failing attempts to access multiple internal devices over the SMB file-sharing protocol, with a range of different usernames. This implies bruteforce network access, as the threat actor attempted to guess correct account details through trial and error.

Existing tools such as RDP and Windows Service Control reveal that the attacker was employing ‘Living off the Land’ techniques. This makes a system administrator’s job inherently harder, as they must distinguish the malicious use of built-in tools versus their legitimate application.

Crypto-mining begins

Finally, the compromised server completed the lateral movement by transferring suspicious executable files over SMB to multiple internal devices, with names that appear randomly generated (e.g. gMtWAvEc.exe, daSsZhPf.exe) to deploy crypto-mining malware using the Minergate protocol.

Minergate is a public mining pool utilized for several types of cryptocurrency including Bitcoin, Monero, Ethereum, Zcash, and Grin. In recent months, ransomware actors have begun shifting away from Bitcoin towards Monero and other more anonymous cryptocurrences – but crypto-miners have been using altcoins for years.

Figure 3: The graph shows a clear increase in model breaches on a similar device, which easily identifies the time frame for the compromise.

As this was part of a trial, Antigena – Darktrace’s Autonomous Response capability – was not in active mode and so could not take action to stop the initial vector of infection. However, the Antigena model “Antigena / Network / External Threat / Antigena Suspicious File Block” was breached on July 18 at 03:55:45. If active, Antigena would have instantly blocked connections to 167.71.87[.]85 on port 80 for two hours, allowing the security team enough time to remediate the breach.

Crypto-mining malware: All the rage

Crypto-mining attacks are extremely common. Although not as destructive as ransomware, they can have a serious impact on network latency and take a long time to detect and clean up. While the infection remains unnoticed, it provides a backdoor into the victim organization – and could switch from conducting crypto-mining to delivering ransomware at any moment. In this case, it is clear the attacker aimed to create maximum disruption by transferring malicious software with targets such as internal servers and domain controllers.

Darktrace detected every step of the attack without relying on known indicators of threat. Cyber AI Analyst automated the complete investigation process, saving the security team crucial time during the live incident.

Especially with the recent crackdowns on Bitcoin farms in China, underground botnets and cloud-based crypto-mining are likely to become more prominent. As we see more of these intrusions in the near future, AI-powered detection, investigation, and response, will prove critical in defending organizations of all sizes, at all times.

Learn more about crypto-mining malware

IoCs:

IoCComment167.71.87[.]85Malware Download — SHA1: 6a4c477ba19a7bb888540d02acdd9be0d5d3fd02VirusTotalt[.]amynx[.]comHTTP Command and Control – recently created domain with suspicious indicators on OSINT sites (associated with cryptomining trojans)AlienVaultVirusTotallplp[.]ackng[.]comCrypto Currency Mining Activity (Minergate)VirusTotalgMtWAvEc.exedaSsZhPf.exeyAElKPQi.exeExamples of malicious executables

Darktrace model breaches:

  • Antigena / Network / Insider Threat / Antigena Network Scan Block
  • Device / Suspicious Network Scan Activity
  • Device / Large Number of Model Breaches
  • Device / Multiple Lateral Movement Model Breaches (x2)
  • Unusual Activity / Successful Admin Bruteforce Activity
  • Anomalous Connection / SMB Enumeration
  • Antigena / Network / Significant Anomaly / Antigena Controlled and Model Breach (x2)
  • Antigena / Network / External Threat / Antigena Suspicious File Block
  • Compromise / Beacon to Young Endpoint (x4)
  • Device / Possible RPC Lateral Movement
  • Antigena / Network / Insider Threat / Antigena SMB Enumeration Block
  • Compromise / Beaconing Activity To External Rare (x5)
  • Anomalous Server Activity / Denial of Service Activity
  • Antigena / Network / External Threat / Antigena Suspicious Activity Block (x4)
  • Device / Large Number of Connections to New Endpoints
  • Device / Network Scan - Low Anomaly Score
  • Anomalous Connection / New or Uncommon Service Control (x3)
  • Device / New User Agent To Internal Server
  • Device / Anomalous RDP Followed By Multiple Model Breaches (x3)
  • Device / Anomalous SMB Followed By Multiple Model Breaches (x3)
  • Device / SMB Session Bruteforce (x2)
  • Device / Increased External Connectivity
  • Device / Network Scan
  • Compromise / High Volume of Connections with Beacon Score (x5)
  • Unusual Activity / Unusual External Activity (x3)
  • Anomalous Connection / Unusual Admin SMB Session
  • Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block
  • Compliance / SMB Drive Write (x3)
  • Antigena / Network / Significant Anomaly / Antigena Breaches Over Time Block (x14)
  • Compliance / Internet Facing RDP Server
  • Anomalous Connection / Multiple Failed Connections to Rare Endpoint (x5)
  • Compliance / Outbound RDP (x3)
  • Anomalous Server Activity / Rare External from Server (x5)
  • Compromise / Slow Beaconing Activity To External Rare (x8)
  • Anomalous Server Activity / Outgoing from Server (x2)
  • Device / New User Agent
  • Anomalous Connection / New Failed External Windows Connection (x5)
  • Compliance / External Windows Communications
  • Device / New Failed External Connections (x7)
  • Compliance / Crypto Currency Mining Activity (x9)
  • Compliance / Incoming Remote Desktop (x9)

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
Max Heinemeyer
Global Field CISO

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April 22, 2025

Obfuscation Overdrive: Next-Gen Cryptojacking with Layers

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Out of all the services honeypotted by Darktrace, Docker is the most commonly attacked, with new strains of malware emerging daily. This blog will analyze a novel malware campaign with a unique obfuscation technique and a new cryptojacking technique.

What is obfuscation?

Obfuscation is a common technique employed by threat actors to prevent signature-based detection of their code, and to make analysis more difficult. This novel campaign uses an interesting technique of obfuscating its payload.

Docker image analysis

The attack begins with a request to launch a container from Docker Hub, specifically the kazutod/tene:ten image. Using Docker Hub’s layer viewer, an analyst can quickly identify what the container is designed to do. In this case, the container is designed to run the ten.py script which is built into itself.

 Docker Hub Image Layers, referencing the script ten.py.
Figure 1: Docker Hub Image Layers, referencing the script ten.py.

To gain more information on the Python file, Docker’s built in tooling can be used to download the image (docker pull kazutod/tene:ten) and then save it into a format that is easier to work with (docker image save kazutod/tene:ten -o tene.tar). It can then be extracted as a regular tar file for further investigation.

Extraction of the resulting tar file.
Figure 2: Extraction of the resulting tar file.

The Docker image uses the OCI format, which is a little different to a regular file system. Instead of having a static folder of files, the image consists of layers. Indeed, when running the file command over the sha256 directory, each layer is shown as a tar file, along with a JSON metadata file.

Output of the file command over the sha256 directory.
Figure 3: Output of the file command over the sha256 directory.

As the detailed layers are not necessary for analysis, a single command can be used to extract all of them into a single directory, recreating what the container file system would look like:

find blobs/sha256 -type f -exec sh -c 'file "{}" | grep -q "tar archive" && tar -xf "{}" -C root_dir' \;

Result of running the command above.
Figure 4: Result of running the command above.

The find command can then be used to quickly locate where the ten.py script is.

find root_dir -name ten.py

root_dir/app/ten.py

Details of the above ten.py script.
Figure 5: Details of the above ten.py script.

This may look complicated at first glance, however after breaking it down, it is fairly simple. The script defines a lambda function (effectively a variable that contains executable code) and runs zlib decompress on the output of base64 decode, which is run on the reversed input. The script then runs the lambda function with an input of the base64 string, and then passes it to exec, which runs the decoded string as Python code.

To help illustrate this, the code can be cleaned up to this simplified function:

def decode(input):
   reversed = input[::-1]

   decoded = base64.decode(reversed)
   decompressed = zlib.decompress(decoded)
   return decompressed

decoded_string = decode(the_big_text_blob)
exec(decoded_string) # run the decoded string

This can then be set up as a recipe in Cyberchef, an online tool for data manipulation, to decode it.

Use of Cyberchef to decode the ten.py script.
Figure 6: Use of Cyberchef to decode the ten.py script.

The decoded payload calls the decode function again and puts the output into exec. Copy and pasting the new payload into the input shows that it does this another time. Instead of copy-pasting the output into the input all day, a quick script can be used to decode this.

The script below uses the decode function from earlier in order to decode the base64 data and then uses some simple string manipulation to get to the next payload. The script will run this over and over until something interesting happens.

# Decode the initial base64

decoded = decode(initial)
# Remove the first 11 characters and last 3

# so we just have the next base64 string

clamped = decoded[11:-3]

for i in range(1, 100):
   # Decode the new payload

   decoded = decode(clamped)
   # Print it with the current step so we

   # can see what’s going on

   print(f"Step {i}")

   print(decoded)
   # Fetch the next base64 string from the

   # output, so the next loop iteration will

   # decode it

   clamped = decoded[11:-3]

Result of the 63rd iteration of this script.
Figure 7: Result of the 63rd iteration of this script.

After 63 iterations, the script returns actual code, accompanied by an error from the decode function as a stopping condition was never defined. It not clear what the attacker’s motive to perform so many layers of obfuscation was, as one round of obfuscation versus several likely would not make any meaningful difference to bypassing signature analysis. It’s possible this is an attempt to stop analysts or other hackers from reverse engineering the code. However,  it took a matter of minutes to thwart their efforts.

Cryptojacking 2.0?

Cleaned up version of the de-obfuscated code.
Figure 8: Cleaned up version of the de-obfuscated code.

The cleaned up code indicates that the malware attempts to set up a connection to teneo[.]pro, which appears to belong to a Web3 startup company.

Teneo appears to be a legitimate company, with Crunchbase reporting that they have raised USD 3 million as part of their seed round [1]. Their service allows users to join a decentralized network, to “make sure their data benefits you” [2]. Practically, their node functions as a distributed social media scraper. In exchange for doing so, users are rewarded with “Teneo Points”, which are a private crypto token.

The malware script simply connects to the websocket and sends keep-alive pings in order to gain more points from Teneo and does not do any actual scraping. Based on the website, most of the rewards are gated behind the number of heartbeats performed, which is likely why this works [2].

Checking out the attacker’s dockerhub profile, this sort of attack seems to be their modus operandi. The most recent container runs an instance of the nexus network client, which is a project to perform distributed zero-knowledge compute tasks in exchange for cryptocurrency.

Typically, traditional cryptojacking attacks rely on using XMRig to directly mine cryptocurrency, however as XMRig is highly detected, attackers are shifting to alternative methods of generating crypto. Whether this is more profitable remains to be seen. There is not currently an easy way to determine the earnings of the attackers due to the more “closed” nature of the private tokens. Translating a user ID to a wallet address does not appear to be possible, and there is limited public information about the tokens themselves. For example, the Teneo token is listed as “preview only” on CoinGecko, with no price information available.

Conclusion

This blog explores an example of Python obfuscation and how to unravel it. Obfuscation remains a ubiquitous technique employed by the majority of malware to aid in detection/defense evasion and being able to de-obfuscate code is an important skill for analysts to possess.

We have also seen this new avenue of cryptominers being deployed, demonstrating that attackers’ techniques are still evolving - even tried and tested fields. The illegitimate use of legitimate tools to obtain rewards is an increasingly common vector. For example,  as has been previously documented, 9hits has been used maliciously to earn rewards for the attack in a similar fashion.

Docker remains a highly targeted service, and system administrators need to take steps to ensure it is secure. In general, Docker should never be exposed to the wider internet unless absolutely necessary, and if it is necessary both authentication and firewalling should be employed to ensure only authorized users are able to access the service. Attacks happen every minute, and even leaving the service open for a short period of time may result in a serious compromise.

References

1. https://www.crunchbase.com/funding_round/teneo-protocol-seed--a8ff2ad4

2. https://teneo.pro/

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About the author
Nate Bill
Threat Researcher

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April 22, 2025

How NDR and Secure Access Service Edge (SASE) Work Together to Achieve Network Security Outcomes

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Modern networks are evolving rapidly, with traffic patterns, user behavior, and critical assets extending far beyond the boundaries of traditional network security tools. As organizations adopt hybrid infrastructures, remote working, and cloud-native services, it is essential to maintain visibility and protect this expanding attack surface.

Network Detection and Response (NDR) and Secure Access Service Edge (SASE) are two technologies commonly used to safeguard organizational networks. While both play crucial roles in enhancing security, one does not replace the other. Instead, NDR and SASE complement each other, taking on different roles to create a robust network security framework. This blog will unpack the relationship between NDR and SASE, including the component functionalities that comprise SASE, highlighting their unique contributions to maintaining a comprehensive and resilient network security strategy.

Network Detection and Response (NDR) and Secure Access Service Edge (SASE) explained

NDR solutions, such as Darktrace / NETWORK, are designed to detect, investigate, and respond to suspicious activities within any network. By leveraging machine learning and behavioral analytics, NDR continuously monitors network traffic to identify anomalies that could indicate potential threats and to contain those threats at machine speed. These solutions analyze both North-South traffic (between internal and external networks) and East-West traffic (within internal networks), providing comprehensive visibility into network activities.

SASE, on the other hand, comprises multiple solutions, focused on providing hybrid and remote users access to services while adhering to the Zero Trust principle of "never trust, always verify". Within SASE architectures, Zero Trust Network Access (ZTNA) solutions provide secure remote access to private applications and services the user has been explicitly granted, and Secure Web Gateways (SWG) provide Internet access, again based on policy groups. Unlike traditional security models that grant implicit trust to users within the network perimeter, ZTNA requires continuous verification of user identity and device health before granting access to resources. This approach minimizes the attack surface and reduces the risk of unauthorized access to sensitive data and internal applications. Similarly, SWGs filter web traffic based on the verified user identity and can block known malware, further reducing the attack surface for the client estate.

Limitations of SASE highlights the importance of NDR

While SASE, including ZTNA and SWG, is a powerful tool for enforcing secure access to company networks and resources as well as the Internet, it is not a comprehensive security solution, or a replacement for dedicated network monitoring and NDR capabilities. Some of the main limitations include:

  • Focused on policies rather than security: SASE delivers strong networking outcomes but provides policy-based protections, rather than a full suite of security features. It can provide simple alerting for disallowed actions, but it lacks the security context needed for comprehensive threat detection, such as knowing if user credentials have been compromised.
  • Can only detect known threats: SASE solutions cannot detect novel attacks such as zero-days and insider threats. This is because they rely on a rule-based approach that does not have a behavioral understanding of network entities that can detect anomalies or suspicious activity.
  • Limited response capabilities: Due to the limited detection capabilities of SASE solutions, it is not possible to automate response actions to threats that slip past existing policies.  While access to internal resources and the Internet can be revoked or severely limited as part of a response, this must be done after human investigation and analysis, allowing more time for the threat to continue before being contained.
  • Limited scope: SASE provides cloud-hosted secure networking, which lends itself much more toward the client estate of any organization. As a result, servers and unmanaged devices—whether IT/IoT/OT—are mostly out of scope and do not benefit from the policies SASE enforces.

The complementary roles of NDR and ZTNA

NDR solutions provide full visibility into network activity, with the ability to detect and respond to threats that may bypass initial access controls and filters. When combined, NDR and SASE create a layered security approach that addresses different aspects of network security, for example:

  • Detection of novel, unknown and insider threats: NDR solutions can monitor all network traffic using behavioral anomaly detection. This can identify suspicious activities, such as insider threats from authorized users who have passed policy checks, or novel attacks that have never been seen before.
  • Validation of policies: By continuously monitoring network traffic, NDR can validate the effectiveness of existing policies and identify any gaps in security that need addressing due to organizational changes or outdated rule sets.
  • Reducing risk and impact of threats: Together, SASE and NDR solutions shift toward proactive security by reducing the potential impact of a threat through predefined policies and by detecting and containing a threat in its earliest stages, even if it is novel or nuanced.
  • Enhanced contextual information: Alerts raised by SASE solutions can provide additional context into potential threats, which can be used by NDR solutions to increase investigation quality and context.
  • Containment of network threats: SASE solutions can prohibit access to resources on an internal company network or on the Internet if predefined access control criteria are not met or a site matches a threat signature. When combined with an NDR solution, organizations can go far beyond this, detecting and responding to a much wider variety of network threats to prevent attacks from escalating.

When implementing SASE and NDR solutions, it is also crucial to consider the best configurations to maximize interoperability, and integrations will often increase functionality. Well-designed implementations, combined with integrations, will strengthen both SASE and NDR solutions for organizations.

How Darktrace continues to secure SASE networks

With the latest 6.3 update, Darktrace continues to extend its capabilities with new innovations that support modern enterprise networks and the use of SASE across remote and hybrid worker devices. This expands on existing Darktrace integrations and partnerships with SASE vendors such as Netskope and Zscaler.

Traditional methods to contain remote access and internet-born threats are either signature or policy based, and response to nuanced threats requires manual, human-led investigation and decision-making. By the time security teams can react, the damage is often already done.

With Darktrace 6.3, customers using Zscaler can now configure Darktrace Autonomous Response to quarantine ZPA-connected user devices at machine speed. This provides a powerful new mechanism for containing remote threats at the earliest sign of suspicious activity, without disrupting broader operations.

By automatically shutting down ZPA access for compromised user accounts, Darktrace gives SOC teams valuable time to investigate and respond, while continuing to protect the rest of the organization. This integration enhances Darktrace’s ability to take actions for remote user devices, helping customers contain threats faster and keep the business running smoothly.

For organizations using SASE technologies to address the challenges of securing large, distributed networks across a range of geographies, SaaS applications and remote worker devices, Darktrace also now integrates with Netskope Cloud TAP to provide visibility into and analysis over tunneled traffic, reducing blind spots and enabling organizations to maintain detection capabilities across their expanding network perimeters.

Conclusion

While NDR and ZTNA serve distinct purposes, their integration is crucial for a comprehensive security strategy. ZTNA provides robust access controls, ensuring that only authorized users can access network resources. NDR, on the other hand, offers continuous visibility into network activities, detecting and responding to threats that may bypass initial access controls. By leveraging the strengths of both solutions, organizations can enhance their security posture and protect against a wide range of network security threats.

Understanding the complementary roles of NDR and ZTNA is essential for building a resilient security framework. As cyber threats continue to evolve, adopting a multi-layered, defense-in-depth security approach will be key to safeguarding organizational networks.

Click here for more information about the latest product innovations in Darktrace 6.3, or learn more about Darktrace / NETWORK here.

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About the author
Mikey Anderson
Product Marketing Manager, Network Detection & Response
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