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February 24, 2021

LockBit Ransomware Analysis: Compromised Credentials

Darktrace examines how a LockBit ransomware attack that took place over just four hours was caused by one compromised credential. Read more here.
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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24
Feb 2021

Lockbit ransomware found

LockBit ransomware was recently identified by Darktrace's Cyber AI during a trial with a retail company in the US. After an initial foothold was established via a compromised administrative credential, internal reconnaissance, lateral movement, and encryption of files occurred simultaneously, allowing the ransomware to steamroll through the digital system in just a few hours.

This incident serves as the latest reminder that ransomware campaigns now move through organizations at a speed that far outpaces human responders, demonstrating the need for machine-speed Autonomous Response to contain the threat before damage is done.

Lockbit ransomware defined

First discovered in 2019, LockBit is a relatively new family of ransomware that quickly exploits commonly available protocols and tools like SMB and PowerShell. It was originally known as ‘ABCD’ due the filename extension of the encrypted files, before it started using the current .lockbit extension. Since those early beginnings, it has evolved into one of the most calamitous strains of malware to date, asking for an average ransom of around $40,000 per organization.

As cyber-criminals level up the speed and scale of their attacks, ransomware remains a critical concern for organizations across every industry. In the past 12 months, Darktrace has observed an increase of over 20% in ransomware incidents across its customer base. Attackers are constantly developing new threat variants targeting exploits, utilizing off-the-shelf tools, and profiting from the burgeoning Ransomware-as-a-Service (RaaS) business model.

How does LockBit work?

In a typical attack, a threat actor will spend days or weeks inside a system, manually screening for the best way to grind the victim’s business to a halt. This phase tends to expose multiple indicators of compromise such as command and control (C2) beaconing, which Darktrace AI identifies in real time.

LockBit, however, only requires the presence of a human for a number of hours, after which it propagates through a system and infects other hosts on its own, without the need for human oversight. Crucially, the malware performs reconnaissance and continues to spread during the encryption phase. This allows it to cause maximal damage faster than other manual approaches.

AI-powered defense is essential in fighting back against these machine-driven attacks, which have the capacity to spread at speed and scale, and often go undetected by signature-based security tools. Cyber AI augments human teams by not only detecting the subtle signs of a threat, but autonomously responding in seconds, quicker than any human can be expected to react.

Ransomware analysis: Breaking down a LockBit attack with AI

Figure 1: Timeline of attack on the infected host and the encryption host. The infected host was the device initially infected with LockBit, which then spread to the encryption host, the device which performed the encryption.

Initial compromise

The attack commenced when a cyber-criminal gained access to a single privileged credential – either through a brute-force attack on an externally facing device, as seen in previous LockBit ransomware attacks, or simply with a phishing email. With the use of this credential, the device was able to spread and encrypt files within hours of the initial infection.

Had the method of infiltration been via phishing attack, a route that has become increasingly popular in recent months, Darktrace/ EMAIL would have withheld the email and stripped the malicious payloads, and so prevented the attack from the outset.

Limiting permissions, the use of strong passwords, and multi-factor authentication (MFA), are critical in preventing the exploitation of standard network protocols in such attacks.

Internal reconnaissance

At 14:19 local time, the first of many WMI commands (ExecMethod) to multiple internal destinations was performed by an internal IP address over DCE-RPC. This series of commands occurred throughout the encryption process. Given these commands were unusual in the context of the normal ‘pattern of life’ for the organization, Darktrace DETECT alerted the security team to each of these connections.

Within three minutes, the device had started to write executable files over SMB to hidden shares on multiple destinations – many of which were the same. File writes to hidden shares are ordinarily restricted. However, the unauthorized use of an administrative credential granted these privileges. The executable files were written to the Windows / Temp directory. Filenames had a similar formatting: .*eck[0-9]?.exe

Darktrace identified each of these SMB writes as a potential threat, since such administrative activity was unexpected from the compromised device.

The WMI commands and executable file writes continued to be made to multiple destinations. In less than two hours, the ExecMethod command was delivered to a critical device – the ‘encryption host’ – shortly followed by an executable file write (eck3.exe) to its hidden c$ share.

LockBit’s script has the capability to check its current privileges and, if non-administrative, it attempts to bypass using Windows User Account Control (UAC). This particular host did provide the required privileges to the process. Once this device was infected, encryption began.

File encryption

Only one second after encryption had started, Darktrace alerted on the unusual file extension appendage in addition to the previous, high-fidelity alerts for earlier stages of the attack lifecycle.

A recovery file – ‘Restore-My-Files.txt’ – was identified by Darktrace one second after the first encryption event. 8,998 recovery files were written, one to each encrypted folder.

An example of Darktrace’s Threat Visualizer showcasing anomalous SMB connections, with model breaches represented by dots.
Figure 2: An example of Darktrace’s Threat Visualizer showcasing anomalous SMB connections, with model breaches represented by dots.

The encryption host was a critical device that regularly utilized SMB. Exploiting SMB is a popular tactic for cyber-criminals. Such tools are so frequently used that it is difficult for signature-based detection methods to identify quickly whether their activity is malicious or not. In this case, Darktrace’s ‘Unusual Activity’ score for the device was elevated within two seconds of the first encryption, indicating that the device was deviating from its usual pattern of behavior.

Throughout the encryption process, Darktrace also detected the device performing network reconnaissance, enumerating shares on 55 devices (via srvsvc) and scanning over 1,000 internal IP addresses on nine critical TCP ports.

During this time, ‘Patient Zero’ – the initially infected device – continued to write executable files to hidden file shares. LockBit was using the initial device to spread the malware across the digital estate, while the ‘encryption host’ performed reconnaissance and encrypted the files simultaneously.

Despite Cyber AI detecting the threat even before the encryption had begun, the security team did not have eyes on Darktrace at the time of the attack. The intrusion was thus allowed to continue and over 300,000 files were encrypted and appended with the .lockbit extension. Four servers and 15 desktop devices were affected, before the attack was stopped by the administrators.

The rise of ‘hit and run’ ransomware

While most ransomware resides inside an organization for days or weeks, LockBit’s self-governing nature allows the attacker to ‘hit and run’, deploying the ransomware with minimal interaction required after the initial intrusion. The ability to detect anomalous activity across the entire digital infrastructure in real time is therefore crucial in LockBit’s prevention.

WMI and SMB are relied upon by the vast majority of companies around the world, and yet they were utilized in this attack to propagate through the system and encrypt hundreds of thousands of files. The prevalence and volume of these connections make them near-impossible to monitor with humans or signature-based detection techniques alone.

Moreover, the uniqueness of every enterprise’s digital estate impedes signature-based detection from effectively alerting on internal connections and the volume of such connections. Darktrace, however, uses machine learning to understand the individual pattern of behavior for each device, in this case allowing it to highlight the unusual internal activity as it occurred.

The organization involved did not have Darktrace’s Autonomous Response technology configured in active mode. If enabled, i would have surgically blocked the initial WMI operations and SMB drive writes that triggered the attack whilst allowing the critical network devices to continue standard operations. Even if the foothold had been established, D would have enforced the ‘pattern of life’ of the encryption host, preventing the cascade of encryption over SMB. This demonstrates the importance of meeting machine-speed attacks with autonomous cyber security, which reacts in real time to sophisticated threats when human security teams cannot.

LockBit has the ability to encrypt thousands of files in just seconds, even when targeting well-prepared organizations. This type of ransomware, with built-in worm-like functionality, is expected to become increasingly common over 2021. Such attacks can move at a speed which no human security team alone can match. Darktrace’s approach, which uses unsupervised machine learning, can respond in seconds to these rapid attacks and shut them down in their earliest stages.

Thanks to Darktrace analyst Isabel Finn for her insights on the above threat find.

Darktrace model detections:

  • Device / New or Uncommon WMI Activity
  • Compliance / SMB Drive Write
  • Compromise / Ransomware / Suspicious SMB Activity
  • Compromise / Ransomware / Ransom or Offensive Words Written to SMB
  • Anomalous File / Internal / Additional Extension Appended to SMB File
  • Anomalous Connection / SMB Enumeration
  • Device / Network Scan – Low Anomaly Score
  • Anomalous Connection / Sustained MIME Type Conversion
  • Anomalous Connection / Suspicious Read Write Ratio
  • Unusual Activity / Sustained Anomalous SMB Activity
  • Device / Large Number of Model Breaches

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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