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November 20, 2023

Mitigating Sectop RAT: Darktrace's Strategy

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20
Nov 2023
Read how Darktrace tackled the Sectop Remote Access Trojan. Gain insights into their advanced threat mitigation strategies.

Introduction

As malicious actors across the threat landscape continue to look for new ways to gain unauthorized access to target networks, it is unsurprising to see Remote Access Trojans (RATs) leveraged more and more. These RATs are downloaded discretely without the target’s knowledge, typically through seemingly legitimate software downloads, and are designed to gain highly privileged network credentials, ultimately allowing attackers to have remote control over compromised devices. [1]

SectopRAT is one pertinent example of a RAT known to adopt a number of stealth functions in order to gather and exfiltrate sensitive data from its targets including passwords, cookies, autofill and history data stores in browsers, as well as cryptocurrency wallet details and system hardware information. [2]

In early 2023, Darktrace identified a resurgence of the SectopRAT across customer environments, primarily targeting educational industries located in the United States (US), Europe, the Middle East and Africa (EMEA) and Asia-Pacific (APAC) regions. Darktrace DETECT™ was able to successfully identify suspicious activity related to SectopRAT at the network level, as well as any indicators of post-compromise on customer environments that did not have Darktrace RESPOND™ in place to take autonomous preventative action.

What is SectopRAT?

First discovered in early 2019, the SectopRAT is a .NET RAT that contains information stealing capabilities. It is also known under the alias ‘ArechClient2’, and is commonly distributed through drive-by downloads of illegitimate software and utilizes malvertising, including via Google Ads, to increase the chances of it being downloaded.

The malware’s code was updated at the beginning of 2021, which led to refined and newly implemented features, including command and control (C2) communication encryption with Advanced Encryption Stanard 256 (AES256) and additional commands. SectopRAT also has a function called "BrowserLogging", ultimately sending any actions it conducts on web browsers to its C2 infrastructure. When the RAT is executed, it then connects to a Pastebin associated hostname to retrieve C2 information; the requested file reaches out to get the public IP address of the infected device. To receive commands, it connects to its C2 server primarily on port 15647, although other ports have been highlighted by open source intelligence (OSINT), which include 15678, 15649, 228 and 80. Ultimately, sensitive data data gathered from target networks is then exfiltrated to the attacker’s C2 infrastructure, typically in a JSON file [3].

Darktrace Coverage

During autonomous investigations into affected customer networks, Darktrace DETECT was able to identify SSL connections to the endpoint pastebin[.]com over port 443, followed by failed connections to one of the IPs and ports (i.e., 15647, 15648, 15649) associated with SectopRAT. This resulted in the devices breaching the ‘Compliance/Pastebin and Anomalous Connection/Multiple Failed Connections to Rare Endpoint’ models, respectively.

In some instances, Darktrace observed a higher number of attempted connections that resulted in the additional breach of the model ‘Compromise / Large Number of Suspicious Failed Connections’.

Over a period of three months, Darktrace investigated multiple instances of SectopRAT infections across multiple clients, highlighting indicators of compromise (IoCs) through related endpoints.Looking specififically at one customer’s activity which centred on January 25, 2023, one device was observed initially making suspicious connections to a Pastebin endpoint, 104.20.67[.]143, likely in an attempt to receive C2 information.

Darktrace DETECT recognized this activity as suspicious, causing the 'Compliance / Pastebin' DETECT models to breach. In response to this detection, Darktrace RESPOND took swift action against the Pastebin connections by blocking them and preventing the device from carrying out further connections with Pastebin endpoints. Darktrace RESPOND actions related to blocking Pastebin connections were commonly observed on this device throughout the course of the attack and likely represented threat actors attempting to exfiltrate sensitive data outside the network.

Darktrace UI image
Figure 1: Model breach event log highlighting the Darktrace DETECT model breach ‘Compliance / Pastebin’.

Around the same time, Darktrace observed the device making a large number of failed connections to an unusual exernal location in the Netherlands, 5.75.147[.]135, via port 15647. Darktrace recognized that this endpoint had never previously been observed on the customer’s network and that the frequency of the failed connections could be indicative of beaconing activity. Subsequent investigation into the endpoint using OSINT indicated it had links to malware, though Darktrace’s successful detection did not need to rely on this intelligence.

Darktrace model breach event log
Figure 2: Model breach event log highlighting the multiple failed connectiosn to the suspicious IP address, 5.75.147[.]135 on January 25, 2023, causing the Darktrace DETECT model ‘Anomalous Connection / Multiple Failed Connections to Rare Endpoint’ to breach.

After these initial set of breaches on January 25, the same device was observed engaging in further external connectivity roughly a month later on February 27, including additional failed connections to the IP 167.235.134[.]14 over port 15647. Once more, multiple OSINT sources revealed that this endpoint was indeed a malicious C2 endpoint.

Darktrace model breach event log 2
Figure 3: Model breach event log highlighting the multiple failed connectiosn to the suspicious IP address, 167.235.134[.]14 on February 27, 2023, causing the Darktrace DETECT model ‘Anomalous Connection / Multiple Failed Connections to Rare Endpoint’ to breach.

While the initial Darktrace coverage up to this point has highlighted the attempted C2 communication and how DETECT was able to alert on the suspicious activity, Pastebin activity was commonly observed throughout the course of this attack. As a result, when enabled in autonomous response mode, Darktrace RESPOND was able to take swift mitigative action by blocking all connections to Pastebin associated hostnames and IP addresses. These interventions by RESPOND ultimately prevented malicious actors from stealing sensitive data from Darktrace customers.

Darktrace RESPOND action list
Figure 4: A total of nine Darktrace RESPOND actions were applied against suspicious Pastebin activity during the course of the attack.

In another similar case investigated by the Darktrace, multiple devices were observed engaging in external connectivity to another malicious endpoint,  88.218.170[.]169 (AS207651 Hosting technology LTD) on port 15647.  On April 17, 2023, at 22:35:24 UTC, the breach device started making connections; of the 34 attempts, one connection was successful – this connection lasted 8 minutes and 49 seconds. Darktrace DETECT’s Self-Learning AI understood that these connections represented a deviation from the device’s usual pattern of behavior and alerted on the activity with the ‘Multiple Connections to new External TCP Port’ model.

Darktrace model breach event log
Figure 5: Model breach event log highlighting the affected device successfully connecting to the suspicious endpoint, 88.218.170[.]169.
Darktrace advanced search query
Figure 6: Advanced Search query highlighting the one successful connection to the endpoint 88.218.170[.]169 out of the 34 attempted connections.

A few days later, on April 20, 2023, at 12:33:59 (UTC) the source device connected to a Pastebin endpoint, 172.67.34[.]170 on port 443 using the SSL protocol, that had never previously be seen on the network. According to Advanced Search data, the first SSL connection lasted over two hours. In total, the device made 9 connections to pastebin[.]com and downloaded 85 KB of data from it.

Darktrace UI highlighting connections
Figure 7: Screenshot of the Darktrace UI highlighting the affected device making multiple connections to Pastebin and downloading 85 KB of data.

Within the same minute, Darktrace detected the device beginning to make a large number of failed connections to another suspicious endpoints, 34.107.84[.]7 (AS396982 GOOGLE-CLOUD-PLATFORM) via port 15647. In total the affected device was observed initiating 1,021 connections to this malicious endpoint, all occurring over the same port and resulting the failed attempts.

Darktrace advanced search query 2
Figure 8: Advanced Search query highlighting the affected device making over one thousand connections to the suspicious endpoint 34.107.84[.]7, all of which failed.

Conclusion

Ultimately, thanks to its Self-Learning AI and anomaly-based approach to threat detection, Darktrace was able to preemptively identify any suspicious activity relating to SectopRAT at the network level, as well as post-compromise activity, and bring it to the immediate attention of customer security teams.

In addition to the successful and timely detection of SectopRAT activity, when enabled in autonomous response mode Darktrace RESPOND was able to shut down suspicious connections to endpoints used by threat actors as malicious infrastructure, thus preventing successful C2 communication and potential data exfiltration.

In the face of a Remote Access Trojan, like SectopRAT, designed to steal sensitive corporate and personal information, the Darktrace suite of products is uniquely placed to offer organizations full visibility over any emerging activity on their networks and respond to it without latency, safeguarding their digital estate whilst causing minimal disruption to business operations.

Credit to Justin Torres, Cyber Analyst, Brianna Leddy, Director of Analysis

Appendices

Darktrace Model Detection:

  • Compliance / Pastebin
  • Anomalous Connection / Multiple Failed Connections to Rare Endpoint
  • Compromise / Large Number of Suspicious Failed Connections
  • Anomalous Connection / Multiple Connections to New External TCP Port

List of IoCs

IoC - Type - Description + Confidence

5.75.147[.]135 - IP - SectopRAT C2 Endpoint

5.75.149[.]1 - IP - SectopRAT C2 Endpoint

34.27.150[.]38 - IP - SectopRAT C2 Endpoint

34.89.247[.]212 - IP - SectopRAT C2 Endpoint

34.107.84[.]7 - IP - SectopRAT C2 Endpoint

34.141.16[.]89 - IP - SectopRAT C2 Endpoint

34.159.180[.]55 - IP - SectopRAT C2 Endpoint

35.198.132[.]51 - IP - SectopRAT C2 Endpoint

35.226.102[.]12 - IP - SectopRAT C2 Endpoint

35.234.79[.]173 - IP - SectopRAT C2 Endpoint

35.234.159[.]213 - IP - SectopRAT C2 Endpoint

35.242.150[.]95 - IP - SectopRAT C2 Endpoint

88.218.170[.]169 - IP - SectopRAT C2 Endpoint

162.55.188[.]246 - IP - SectopRAT C2 Endpoint

167.235.134[.]14 - IP - SectopRAT C2 Endpoint

MITRE ATT&CK Mapping

Model: Compliance / Pastebin

ID: T1537

Tactic: EXFILTRATION

Technique Name: Transfer Data to Cloud Account

Model: Anomalous Connection / Multiple Failed Connections to Rare Endpoint

ID: T1090.002

Sub technique of: T1090

Tactic: COMMAND AND CONTROL

Technique Name: External Proxy

ID: T1095

Tactic: COMMAND AND CONTROL

Technique Name: Non-Application Layer Protocol

ID: T1571

Tactic: COMMAND AND CONTROL

Technique Name: Non-Standard Port

Model: Compromise / Large Number of Suspicious Failed Connections

ID: T1571

Tactic: COMMAND AND CONTROL

Technique Name: Non-Standard Port

ID: T1583.006

Sub technique of: T1583

Tactic: RESOURCE DEVELOPMENT

Technique Name: Web Services

Model: Anomalous Connection / Multiple Connections to New External TCP Port

ID: T1095        

Tactic: COMMAND AND CONTROL    

Technique Name: Non-Application Layer Protocol

ID: T1571

Tactic: COMMAND AND CONTROL    

Technique Name: Non-Standard Port

References

1.     https://www.techtarget.com/searchsecurity/definition/RAT-remote-access-Trojan

2.     https://malpedia.caad.fkie.fraunhofer.de/details/win.sectop_rat

3.     https://threatfox.abuse.ch/browse/malware/win.sectop_rat

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.
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Justin Torres
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March 18, 2025

Survey findings: How is AI Impacting the SOC?

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There’s no question that AI is already impacting the SOC – augmenting, assisting, and filling the gaps left by staff and skills shortages. We surveyed over 1,500 cybersecurity professionals from around the world to uncover their attitudes to AI cybersecurity in 2025. Our findings revealed striking trends in how AI is changing the way security leaders think about hiring and SOC transformation. Download the full report for the big picture, available now.

Download the full report to explore these findings in depth

The AI-human conundrum

Let’s start with some context. As the cybersecurity sector has rapidly evolved to integrate AI into all elements of cyber defense, the pace of technological advancement is outstripping the development of necessary skills. Given the ongoing challenges in security operations, such as employee burnout, high turnover rates, and talent shortages, recruiting personnel to bridge these skills gaps remains an immense challenge in today’s landscape.

But here, our main findings on this topic seem to contradict each other.

There’s no question over the impact of AI-powered threats – nearly three-quarters (74%) agree that AI-powered threats now pose a significant challenge for their organization.  

When we look at how security leaders are defending against AI-powered threats, over 3 out of 5 (62%) see insufficient personnel to manage tools and alerts as the biggest barrier.  

Yet at the same time, increasing cyber security staff is at the bottom of the priority list for survey participants, with only 11% planning to increase cybersecurity staff in 2025 – less than in 2024. What 64% of stakeholders are committed to, however, is adding new AI-powered tools onto their existing security stacks.

The conclusion? Due to pressures around hiring, defensive AI is becoming integral to the SOC as a means of augmenting understaffed teams.

How is AI plugging skills shortages in the SOC?

As explored in our recent white paper, the CISO’s Guide to Navigating the Cybersecurity Skills Shortage, 71% of organizations report unfilled cybersecurity positions, leading to the estimation that less than 10% of alerts are thoroughly vetted. In this scenario, AI has become an essential multiplier to relieve the burden on security teams.

95% of respondents agree that AI-powered solutions can significantly improve the speed and efficiency of their defenses. But how?

The area security leaders expect defensive AI to have the biggest impact is on improving threat detection, followed by autonomous response to threats and identifying exploitable vulnerabilities.

Interestingly, the areas that participants ranked less highly (reducing alert fatigue and running phishing simulation), are the tasks that AI already does well and can therefore be used already to relieve the burden of manual, repetitive work on the SOC.

Different perspectives from different sides of the SOC

CISOs and SecOps teams aren’t necessarily aligned on the AI defense question – while CISOs tend to see it as a strategic game-changer, SecOps teams on the front lines may be more sceptical, wary of its real-world reliability and integration into workflows.  

From the data, we see that while less than a quarter of execs doubt that AI-powered solutions will block and automatically respond to AI threats, about half of SecOps aren’t convinced. And only 17% of CISOs lack confidence in the ability of their teams to implement and use AI-powered solutions, whereas over 40% those in the team doubt their own ability to do so.

This gap feeds into the enthusiasm that executives share about adding AI-driven tools into the stack, while day-to-day users of the tools are more interested in improving security awareness training and improving cybersecurity tool integration.

Levels of AI understanding in the SOC

AI is only as powerful as the people who use it, and levels of AI expertise in the SOC can make or break its real-world impact. If security leaders want to unlock AI’s full potential, they must bridge the knowledge gap—ensuring teams understand not just the different types of AI, but where it can be applied for maximum value.

Only 42% of security professionals are confident that they fully understand all the types of AI in their organization’s security stack.

This data varies between job roles – executives report higher levels of understanding (60% say they know exactly which types of AI are being used) than participants in other roles. Despite having a working knowledge of using the tools day-to-day, SecOps practitioners were more likely to report having a “reasonable understanding” of the types of AI in use in their organization (42%).  

Whether this reflects a general confidence in executives rather than technical proficiency it’s hard to say, but it speaks to the importance of AI-human collaboration – introducing AI tools for cybersecurity to plug the gaps in human teams will only be effective if security professionals are supported with the correct education and training.  

Download the full report to explore these findings in depth

The full report for Darktrace’s State of AI Cybersecurity is out now. Download the paper to dig deeper into these trends, and see how results differ by industry, region, organization size, and job title.  

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March 18, 2025

Darktrace's Detection of State-Linked ShadowPad Malware

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An integral part of cybersecurity is anomaly detection, which involves identifying unusual patterns or behaviors in network traffic that could indicate malicious activity, such as a cyber-based intrusion. However, attribution remains one of the ever present challenges in cybersecurity. Attribution involves the process of accurately identifying and tracing the source to a specific threat actor(s).

Given the complexity of digital networks and the sophistication of attackers who often use proxies or other methods to disguise their origin, pinpointing the exact source of a cyberattack is an arduous task. Threat actors can use proxy servers, botnets, sophisticated techniques, false flags, etc. Darktrace’s strategy is rooted in the belief that identifying behavioral anomalies is crucial for identifying both known and novel threat actor campaigns.

The ShadowPad cluster

Between July 2024 and November 2024, Darktrace observed a cluster of activity threads sharing notable similarities. The threads began with a malicious actor using compromised user credentials to log in to the target organization's Check Point Remote Access virtual private network (VPN) from an attacker-controlled, remote device named 'DESKTOP-O82ILGG'.  In one case, the IP from which the initial login was carried out was observed to be the ExpressVPN IP address, 194.5.83[.]25. After logging in, the actor gained access to service account credentials, likely via exploitation of an information disclosure vulnerability affecting Check Point Security Gateway devices. Recent reporting suggests this could represent exploitation of CVE-2024-24919 [27,28]. The actor then used these compromised service account credentials to move laterally over RDP and SMB, with files related to the modular backdoor, ShadowPad, being delivered to the  ‘C:\PerfLogs\’ directory of targeted internal systems. ShadowPad was seen communicating with its command-and-control (C2) infrastructure, 158.247.199[.]185 (dscriy.chtq[.]net), via both HTTPS traffic and DNS tunneling, with subdomains of the domain ‘cybaq.chtq[.]net’ being used in the compromised devices’ TXT DNS queries.

Darktrace’s Advanced Search data showing the VPN-connected device initiating RDP connections to a domain controller (DC). The device subsequently distributes likely ShadowPad-related payloads and makes DRSGetNCChanges requests to a second DC.
Figure 1: Darktrace’s Advanced Search data showing the VPN-connected device initiating RDP connections to a domain controller (DC). The device subsequently distributes likely ShadowPad-related payloads and makes DRSGetNCChanges requests to a second DC.
Event Log data showing a DC making DNS queries for subdomains of ‘cbaq.chtq[.]net’ to 158.247.199[.]185 after receiving SMB and RDP connections from the VPN-connected device, DESKTOP-O82ILGG.
Figure 2: Event Log data showing a DC making DNS queries for subdomains of ‘cbaq.chtq[.]net’ to 158.247.199[.]185 after receiving SMB and RDP connections from the VPN-connected device, DESKTOP-O82ILGG.

Darktrace observed these ShadowPad activity threads within the networks of European-based customers in the manufacturing and financial sectors.  One of these intrusions was followed a few months later by likely state-sponsored espionage activity, as detailed in the investigation of the year in Darktrace’s Annual Threat Report 2024.

Related ShadowPad activity

Additional cases of ShadowPad were observed across Darktrace’s customer base in 2024. In some cases, common C2 infrastructure with the cluster discussed above was observed, with dscriy.chtq[.]net and cybaq.chtq[.]net both involved; however, no other common features were identified. These ShadowPad infections were observed between April and November 2024, with customers across multiple regions and sectors affected.  Darktrace’s observations align with multiple other public reports that fit the timeframe of this campaign.

Darktrace has also observed other cases of ShadowPad without common infrastructure since September 2024, suggesting the use of this tool by additional threat actors.

The data theft thread

One of the Darktrace customers impacted by the ShadowPad cluster highlighted above was a European manufacturer. A distinct thread of activity occurred within this organization’s network several months after the ShadowPad intrusion, in October 2024.

The thread involved the internal distribution of highly masqueraded executable files via Sever Message Block (SMB) and WMI (Windows Management Instrumentation), the targeted collection of sensitive information from an internal server, and the exfiltration of collected information to a web of likely compromised sites. This observed thread of activity, therefore, consisted of three phrases: lateral movement, collection, and exfiltration.

The lateral movement phase began when an internal user device used an administrative credential to distribute files named ‘ProgramData\Oracle\java.log’ and 'ProgramData\Oracle\duxwfnfo' to the c$ share on another internal system.  

Darktrace model alert highlighting an SMB write of a file named ‘ProgramData\Oracle\java.log’ to the c$ share on another device.
Figure 3: Darktrace model alert highlighting an SMB write of a file named ‘ProgramData\Oracle\java.log’ to the c$ share on another device.

Over the next few days, Darktrace detected several other internal systems using administrative credentials to upload files with the following names to the c$ share on internal systems:

ProgramData\Adobe\ARM\webservices.dll

ProgramData\Adobe\ARM\wksprt.exe

ProgramData\Oracle\Java\wksprt.exe

ProgramData\Oracle\Java\webservices.dll

ProgramData\Microsoft\DRM\wksprt.exe

ProgramData\Microsoft\DRM\webservices.dll

ProgramData\Abletech\Client\webservices.dll

ProgramData\Abletech\Client\client.exe

ProgramData\Adobe\ARM\rzrmxrwfvp

ProgramData\3Dconnexion\3DxWare\3DxWare.exe

ProgramData\3Dconnexion\3DxWare\webservices.dll

ProgramData\IDMComp\UltraCompare\updater.exe

ProgramData\IDMComp\UltraCompare\webservices.dll

ProgramData\IDMComp\UltraCompare\imtrqjsaqmm

Cyber AI Analyst highlighting an SMB write of a file named ‘ProgramData\Adobe\ARM\webservices.dll’ to the c$ share on an internal system.
Figure 4: Cyber AI Analyst highlighting an SMB write of a file named ‘ProgramData\Adobe\ARM\webservices.dll’ to the c$ share on an internal system.

The threat actor appears to have abused the Microsoft RPC (MS-RPC) service, WMI, to execute distributed payloads, as evidenced by the ExecMethod requests to the IWbemServices RPC interface which immediately followed devices’ SMB uploads.  

Cyber AI Analyst data highlighting a thread of activity starting with an SMB data upload followed by ExecMethod requests.
Figure 5: Cyber AI Analyst data highlighting a thread of activity starting with an SMB data upload followed by ExecMethod requests.

Several of the devices involved in these lateral movement activities, both on the source and destination side, were subsequently seen using administrative credentials to download tens of GBs of sensitive data over SMB from a specially selected server.  The data gathering stage of the threat sequence indicates that the threat actor had a comprehensive understanding of the organization’s system architecture and had precise objectives for the information they sought to extract.

Immediately after collecting data from the targeted server, devices went on to exfiltrate stolen data to multiple sites. Several other likely compromised sites appear to have been used as general C2 infrastructure for this intrusion activity. The sites used by the threat actor for C2 and data exfiltration purport to be sites for companies offering a variety of service, ranging from consultancy to web design.

Screenshot of one of the likely compromised sites used in the intrusion. 
Figure 6: Screenshot of one of the likely compromised sites used in the intrusion.

At least 16 sites were identified as being likely data exfiltration or C2 sites used by this threat actor in their operation against this organization. The fact that the actor had such a wide web of compromised sites at their disposal suggests that they were well-resourced and highly prepared.  

Darktrace model alert highlighting an internal device slowly exfiltrating data to the external endpoint, yasuconsulting[.]com.
Figure 7: Darktrace model alert highlighting an internal device slowly exfiltrating data to the external endpoint, yasuconsulting[.]com.
Darktrace model alert highlighting an internal device downloading nearly 1 GB of data from an internal system just before uploading a similar volume of data to another suspicious endpoint, www.tunemmuhendislik[.]com    
Figure 8: Darktrace model alert highlighting an internal device downloading nearly 1 GB of data from an internal system just before uploading a similar volume of data to another suspicious endpoint, www.tunemmuhendislik[.]com  

Cyber AI Analyst spotlight

Cyber AI Analyst identifying and piecing together the various steps of a ShadowPad intrusion.
Figure 9: Cyber AI Analyst identifying and piecing together the various steps of a ShadowPad intrusion.  
Cyber AI Analyst Incident identifying and piecing together the various steps of the data theft activity.
Figure 10: Cyber AI Analyst Incident identifying and piecing together the various steps of the data theft activity.

As shown in the above figures, Cyber AI Analyst’s ability to thread together the different steps of these attack chains are worth highlighting.

In the ShadowPad attack chains, Cyber AI Analyst was able to identify SMB writes from the VPN subnet to the DC, and the C2 connections from the DC. It was also able to weave together this activity into a single thread representing the attacker’s progression.

Similarly, in the data exfiltration attack chain, Cyber AI Analyst identified and connected multiple types of lateral movement over SMB and WMI and external C2 communication to various external endpoints, linking them in a single, connected incident.

These Cyber AI Analyst actions enabled a quicker understanding of the threat actor sequence of events and, in some cases, faster containment.

Attribution puzzle

Publicly shared research into ShadowPad indicates that it is predominantly used as a backdoor in People’s Republic of China (PRC)-sponsored espionage operations [5][6][7][8][9][10]. Most publicly reported intrusions involving ShadowPad  are attributed to the China-based threat actor, APT41 [11][12]. Furthermore, Google Threat Intelligence Group (GTIG) recently shared their assessment that ShadowPad usage is restricted to clusters associated with APT41 [13]. Interestingly, however, there have also been public reports of ShadowPad usage in unattributed intrusions [5].

The data theft activity that later occurred in the same Darktrace customer network as one of these ShadowPad compromises appeared to be the targeted collection and exfiltration of sensitive data. Such an objective indicates the activity may have been part of a state-sponsored operation. The tactics, techniques, and procedures (TTPs), artifacts, and C2 infrastructure observed in the data theft thread appear to resemble activity seen in previous Democratic People’s Republic of Korea (DPRK)-linked intrusion activities [15] [16] [17] [18] [19].

The distribution of payloads to the following directory locations appears to be a relatively common behavior in DPRK-sponsored intrusions.

Observed examples:

C:\ProgramData\Oracle\Java\  

C:\ProgramData\Adobe\ARM\  

C:\ProgramData\Microsoft\DRM\  

C:\ProgramData\Abletech\Client\  

C:\ProgramData\IDMComp\UltraCompare\  

C:\ProgramData\3Dconnexion\3DxWare\

Additionally, the likely compromised websites observed in the data theft thread, along with some of the target URI patterns seen in the C2 communications to these sites, resemble those seen in previously reported DPRK-linked intrusion activities.

No clear evidence was found to link the ShadowPad compromise to the subsequent data theft activity that was observed on the network of the manufacturing customer. It should be noted, however, that no clear signs of initial access were found for the data theft thread – this could suggest the ShadowPad intrusion itself represents the initial point of entry that ultimately led to data exfiltration.

Motivation-wise, it seems plausible for the data theft thread to have been part of a DPRK-sponsored operation. DPRK is known to pursue targets that could potentially fulfil its national security goals and had been publicly reported as being active in months prior to this intrusion [21]. Furthermore, the timing of the data theft aligns with the ratification of the mutual defense treaty between DPRK and Russia and the subsequent accused activities [20].

Darktrace assesses with medium confidence that a nation-state, likely DPRK, was responsible, based on our investigation, the threat actor applied resources, patience, obfuscation, and evasiveness combined with external reporting, collaboration with the cyber community, assessing the attacker’s motivation and world geopolitical timeline, and undisclosed intelligence.

Conclusion

When state-linked cyber activity occurs within an organization’s environment, previously unseen C2 infrastructure and advanced evasion techniques will likely be used. State-linked cyber actors, through their resources and patience, are able to bypass most detection methods, leaving anomaly-based methods as a last line of defense.

Two threads of activity were observed within Darktrace’s customer base over the last year: The first operation involved the abuse of Check Point VPN credentials to log in remotely to organizations’ networks, followed by the distribution of ShadowPad to an internal domain controller. The second operation involved highly targeted data exfiltration from the network of one of the customers impacted by the previously mentioned ShadowPad activity.

Despite definitive attribution remaining unresolved, both the ShadowPad and data exfiltration activities were detected by Darktrace’s Self-Learning AI, with Cyber AI Analyst playing a significant role in identifying and piecing together the various steps of the intrusion activities.  

Credit to Sam Lister (R&D Detection Analyst), Emma Foulger (Principal Cyber Analyst), Nathaniel Jones (VP), and the Darktrace Threat Research team.

Appendices

Darktrace / NETWORK model alerts

User / New Admin Credentials on Client

Anomalous Connection / Unusual Admin SMB Session

Compliance / SMB Drive Write  

Device / Anomalous SMB Followed By Multiple Model Breaches

Anomalous File / Internal / Unusual SMB Script Write

User / New Admin Credentials on Client  

Anomalous Connection / Unusual Admin SMB Session

Compliance / SMB Drive Write

Device / Anomalous SMB Followed By Multiple Model Breaches

Anomalous File / Internal / Unusual SMB Script Write

Device / New or Uncommon WMI Activity

Unusual Activity / Internal Data Transfer

Anomalous Connection / Download and Upload

Anomalous Server Activity / Rare External from Server

Compromise / Beacon to Young Endpoint

Compromise / Agent Beacon (Short Period)

Anomalous Server Activity / Anomalous External Activity from Critical Network Device

Anomalous Connection / POST to PHP on New External Host

Compromise / Sustained SSL or HTTP Increase

Compromise / Sustained TCP Beaconing Activity To Rare Endpoint

Anomalous Connection / Multiple Failed Connections to Rare Endpoint

Device / Multiple C2 Model Alerts

Anomalous Connection / Data Sent to Rare Domain

Anomalous Connection / Download and Upload

Unusual Activity / Unusual External Data Transfer

Anomalous Connection / Low and Slow Exfiltration

Anomalous Connection / Uncommon 1 GiB Outbound  

MITRE ATT&CK mapping

(Technique name – Tactic ID)

ShadowPad malware threads

Initial Access - Valid Accounts: Domain Accounts (T1078.002)

Initial Access - External Remote Services (T1133)

Privilege Escalation - Exploitation for Privilege Escalation (T1068)

Privilege Escalation - Valid Accounts: Default Accounts (T1078.001)

Defense Evasion - Masquerading: Match Legitimate Name or Location (T1036.005)

Lateral Movement - Remote Services: Remote Desktop Protocol (T1021.001)

Lateral Movement - Remote Services: SMB/Windows Admin Shares (T1021.002)

Command and Control - Proxy: Internal Proxy (T1090.001)

Command and Control - Application Layer Protocol: Web Protocols (T1071.001)

Command and Control - Encrypted Channel: Asymmetric Cryptography (T1573.002)

Command and Control - Application Layer Protocol: DNS (T1071.004)

Data theft thread

Resource Development - Compromise Infrastructure: Domains (T1584.001)

Privilege Escalation - Valid Accounts: Default Accounts (T1078.001)

Privilege Escalation - Valid Accounts: Domain Accounts (T1078.002)

Execution - Windows Management Instrumentation (T1047)

Defense Evasion - Masquerading: Match Legitimate Name or Location (T1036.005)

Defense Evasion - Obfuscated Files or Information (T1027)

Lateral Movement - Remote Services: SMB/Windows Admin Shares (T1021.002)

Collection - Data from Network Shared Drive (T1039)

Command and Control - Application Layer Protocol: Web Protocols (T1071.001)

Command and Control - Encrypted Channel: Asymmetric Cryptography (T1573.002)

Command and Control - Proxy: External Proxy (T1090.002)

Exfiltration - Exfiltration Over C2 Channel (T1041)

Exfiltration - Data Transfer Size Limits (T1030)

List of indicators of compromise (IoCs)

IP addresses and/or domain names (Mid-high confidence):

ShadowPad thread

- dscriy.chtq[.]net • 158.247.199[.]185 (endpoint of C2 comms)

- cybaq.chtq[.]net (domain name used for DNS tunneling)  

Data theft thread

- yasuconsulting[.]com (45.158.12[.]7)

- hobivan[.]net (94.73.151[.]72)

- mediostresbarbas.com[.]ar (75.102.23[.]3)

- mnmathleague[.]org (185.148.129[.]24)

- goldenborek[.]com (94.138.200[.]40)

- tunemmuhendislik[.]com (94.199.206[.]45)

- anvil.org[.]ph (67.209.121[.]137)

- partnerls[.]pl (5.187.53[.]50)

- angoramedikal[.]com (89.19.29[.]128)

- awork-designs[.]dk (78.46.20[.]225)

- digitweco[.]com (38.54.95[.]190)

- duepunti-studio[.]it (89.46.106[.]61)

- scgestor.com[.]br (108.181.92[.]71)

- lacapannadelsilenzio[.]it (86.107.36[.]15)

- lovetamagotchith[.]com (203.170.190[.]137)

- lieta[.]it (78.46.146[.]147)

File names (Mid-high confidence):

ShadowPad thread:

- perflogs\1.txt

- perflogs\AppLaunch.exe

- perflogs\F4A3E8BE.tmp

- perflogs\mscoree.dll

Data theft thread

- ProgramData\Oracle\java.log

- ProgramData\Oracle\duxwfnfo

- ProgramData\Adobe\ARM\webservices.dll

- ProgramData\Adobe\ARM\wksprt.exe

- ProgramData\Oracle\Java\wksprt.exe

- ProgramData\Oracle\Java\webservices.dll

- ProgramData\Microsoft\DRM\wksprt.exe

- ProgramData\Microsoft\DRM\webservices.dll

- ProgramData\Abletech\Client\webservices.dll

- ProgramData\Abletech\Client\client.exe

- ProgramData\Adobe\ARM\rzrmxrwfvp

- ProgramData\3Dconnexion\3DxWare\3DxWare.exe

- ProgramData\3Dconnexion\3DxWare\webservices.dll

- ProgramData\IDMComp\UltraCompare\updater.exe

- ProgramData\IDMComp\UltraCompare\webservices.dll

- ProgramData\IDMComp\UltraCompare\imtrqjsaqmm

- temp\HousecallLauncher64.exe

Attacker-controlled device hostname (Mid-high confidence)

- DESKTOP-O82ILGG

References  

[1] https://www.kaspersky.com/about/press-releases/shadowpad-how-attackers-hide-backdoor-in-software-used-by-hundreds-of-large-companies-around-the-world  

[2] https://media.kasperskycontenthub.com/wp-content/uploads/sites/43/2017/08/07172148/ShadowPad_technical_description_PDF.pdf

[3] https://blog.avast.com/new-investigations-in-ccleaner-incident-point-to-a-possible-third-stage-that-had-keylogger-capacities

[4] https://securelist.com/operation-shadowhammer-a-high-profile-supply-chain-attack/90380/

[5] https://assets.sentinelone.com/c/Shadowpad?x=P42eqA

[6] https://www.cyfirma.com/research/the-origins-of-apt-41-and-shadowpad-lineage/

[7] https://www.csoonline.com/article/572061/shadowpad-has-become-the-rat-of-choice-for-several-state-sponsored-chinese-apts.html

[8] https://global.ptsecurity.com/analytics/pt-esc-threat-intelligence/shadowpad-new-activity-from-the-winnti-group

[9] https://cymulate.com/threats/shadowpad-privately-sold-malware-espionage-tool/

[10] https://www.secureworks.com/research/shadowpad-malware-analysis

[11] https://blog.talosintelligence.com/chinese-hacking-group-apt41-compromised-taiwanese-government-affiliated-research-institute-with-shadowpad-and-cobaltstrike-2/

[12] https://hackerseye.net/all-blog-items/tails-from-the-shadow-apt-41-injecting-shadowpad-with-sideloading/

[13] https://cloud.google.com/blog/topics/threat-intelligence/scatterbrain-unmasking-poisonplug-obfuscator

[14] https://www.domaintools.com/wp-content/uploads/conceptualizing-a-continuum-of-cyber-threat-attribution.pdf

[15] https://www.nccgroup.com/es/research-blog/north-korea-s-lazarus-their-initial-access-trade-craft-using-social-media-and-social-engineering/  

[16] https://www.microsoft.com/en-us/security/blog/2021/01/28/zinc-attacks-against-security-researchers/

[17] https://www.microsoft.com/en-us/security/blog/2022/09/29/zinc-weaponizing-open-source-software/  

[18] https://www.welivesecurity.com/en/eset-research/lazarus-luring-employees-trojanized-coding-challenges-case-spanish-aerospace-company/  

[19] https://blogs.jpcert.or.jp/en/2021/01/Lazarus_malware2.html  

[20] https://usun.usmission.gov/joint-statement-on-the-unlawful-arms-transfer-by-the-democratic-peoples-republic-of-korea-to-russia/

[21] https://media.defense.gov/2024/Jul/25/2003510137/-1/-1/1/Joint-CSA-North-Korea-Cyber-Espionage-Advance-Military-Nuclear-Programs.PDF  

[22] https://kyivindependent.com/first-north-korean-troops-deployed-to-front-line-in-kursk-oblast-ukraines-military-intelligence-says/

[23] https://www.microsoft.com/en-us/security/blog/2024/12/04/frequent-freeloader-part-i-secret-blizzard-compromising-storm-0156-infrastructure-for-espionage/  

[24] https://www.microsoft.com/en-us/security/blog/2024/12/11/frequent-freeloader-part-ii-russian-actor-secret-blizzard-using-tools-of-other-groups-to-attack-ukraine/  

[25] https://www.sentinelone.com/labs/chamelgang-attacking-critical-infrastructure-with-ransomware/    

[26] https://thehackernews.com/2022/06/state-backed-hackers-using-ransomware.html/  

[27] https://blog.checkpoint.com/security/check-point-research-explains-shadow-pad-nailaolocker-and-its-protection/

[28] https://www.orangecyberdefense.com/global/blog/cert-news/meet-nailaolocker-a-ransomware-distributed-in-europe-by-shadowpad-and-plugx-backdoors

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About the author
Sam Lister
SOC Analyst
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