Securing Operational Technology in Remote Working Conditions
24
Mar 2020
Remote work poses new challenges for cybersecurity professionals. Use these tips to secure your operational technology (OT) in remote working conditions.
Remote work poses new challenges
As organizations rapidly transition to remote working, security professionals tasked with defending critical infrastructure and OT systems are faced with a broad set of challenges. New business measures, many of which were enacted overnight, have introduced risks to OT environments that can be safety-critical. This blog post summarizes the emerging vulnerabilities and offers advice for OT security professionals to stay secure under these evolving and dynamic business conditions.
Remote access
Under new business pressures, operators and engineers are being granted levels of remote access that were previously considered unacceptable risks. Remote access to OT networks has always been a significant threat vector, whether the intended users are company staff or third-party contractors and vendors. Compromised remote access can serve as a launching point for many other malicious or dangerously misguided activities – something referred to many times in the recently released MITRE ATT&CK for ICS matrix under the ‘Initial Access’ and ‘Lateral Movement’ sections. This is especially true in the current period of sweeping and sudden changes in working practices, where staff may not have been trained in advance and static cyber defenses have to be rapidly adjusted. The potential for new oversights and mistakes is at an all-time high.
Many OT security architectures heavily rely on a ‘defense-in-depth’ approach, which involves building multiple layers of defense outside the core OT functions. This has always been vulnerable to a dedicated attacker or an effective worm malware. However, recent measures have seen a rapid escalation in the most dangerous form of remote access, which likely emerges within most of those defensive layers – and without the long planning process that would usually be followed in preparation.
These changes open the door to new vulnerabilities at a time when industrial environments are already experiencing significant operator resource problems. Remote access is not efficient, which means these organizations will already be struggling. Asking these organizations to also take on new security responsibilities, that take time to put in place and facilitate, hugely exacerbates the problem.
Convergence with IT
This transition to remote access exposes some of the longer-term security challenges faced by teams overseeing industrial environments. This includes the historical trend of IT hardware, operating systems, and services invading OT networks for financial efficiency without being suitable for the availability-first environment – hence the difficulty of maintaining up-to-date patching.
The increasing interconnectivity of OT and IT means that defending against an attack on the operational side, whether intentional or as collateral damage, has become of paramount importance. Vulnerable OT equipment is often used as a gateway for a more pernicious attack on the network, and in equal measure, attacks that start in the corporate IT system can result in disruption to physical operations – causing catastrophic losses to production.
Supply chain risk
Physically establishing a test environment may be impossible given the current circumstances, and yet the production environment has to keep running. This may again result in a lower level of testing than was previously acceptable, as well as opening up another vector of attack through the supply chain – as pre-infected hardware and malware can appear directly within the production environment.
In these conditions, carrying out risk and security reviews for all vendors and the products they are purchasing has never been more important. Additional reviews and monitoring of any outsourced or open-sourced components will be critical to mitigate against supply chain risk – but these precautions may be neglected due to current business environments and policies.
An overnight change
The sudden shift in working practices will also expose the limitations of staff training – for example, in what they are supposed to be doing and not doing over remote access. Taken away from the secure environment normally supported by a location in a physical HQ, security professionals and OT engineers will now be working within their own home networks, which invariably will not be as secure as the working environment. The required level of education cannot be rolled out over this short timeframe. As well-meaning employees seek to urgently resolve business obstacles, protocol will inevitably be breached.
Further, sudden changes in static security like firewall rules are destabilizing, and more likely to have errors and unwanted permissions. Alterations to OT systems, in particular safety-critical processes, take enormous forward planning, and it is extremely rare for them to have to take place because of sudden and fundamental change.
Mitigating the risks
The transition to remote working means OT security teams will have to be able to better investigate security incidents without being onsite. This means a marked improvement in visibility and forensic capabilities is required.
The limitations of traditional security tools reliant on rules and signatures of previously identified threats will be thrown into the spotlight under the current circumstances. Organizations will instead need to move to more flexible security platforms that can adapt to sudden business changes. Hundreds of organizations have turned to cyber AI as an ally in enhancing their defense strategy to combat these OT challenges. AI is particularly suited to supporting security teams in this new set of dynamic conditions due to three key features:
The detection capability is consistent across both OT and IT technologies. These are always intermingled in real OT networks, but significant remote access increases the presence of more traditionally IT services and risks.
Its unsupervised machine learning core does not require extensive manual configuration or maintenance. This is particularly crucial at a time when working practices have changed to generally less efficient methods, meaning human resources are now at a premium.
The Cyber AI Analyst advances both of the prior themes even further by automatically applying expert IT and OT analysis skills, saving human analysts large amounts of time on triage and investigation.
The Industrial Immune System can be installed within just one hour, allowing organizations to adapt to these sudden changes within the timeframe required. Darktrace is committed to helping its customers with their urgent cyber security needs at this time of rapid and sudden change.
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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.
Bytesize Security: Insider Threats in Google Workspace
What is an insider threat?
An insider threat is a cyber risk originating from within an organization. These threats can involve actions such as an employee inadvertently clicking on a malicious link (e.g., a phishing email) or an employee with malicious intent conducting data exfiltration for corporate sabotage.
Insiders often exploit their knowledge and access to legitimate corporate tools, presenting a continuous risk to organizations. Defenders must protect their digital estate against threats from both within and outside the organization.
For example, in the summer of 2024, Darktrace / IDENTITY successfully detected a user in a customer environment attempting to steal sensitive data from a trusted Google Workspace service. Despite the use of a legitimate and compliant corporate tool, Darktrace identified anomalies in the user’s behavior that indicated malicious intent.
Attack overview: Insider threat
In June 2024, Darktrace detected unusual activity involving the Software-as-a-Service (SaaS) account of a former employee from a customer organization. This individual, who had recently left the company, was observed downloading a significant amount of data in the form of a “.INDD” file (an Adobe InDesign document typically used to create page layouts [1]) from Google Drive.
While the use of Google Drive and other Google Workspace platforms was not unexpected for this employee, Darktrace identified that the user had logged in from an unfamiliar and suspicious IPv6 address before initiating the download. This anomaly triggered a model alert in Darktrace / IDENTITY, flagging the activity as potentially malicious.
Figure 1: A Model Alert in Darktrace / IDENTITY showing the unusual “.INDD” file being downloaded from Google Workspace.
Following this detection, the customer reached out to Darktrace’s Security Operations Center (SOC) team via the Security Operations Support service for assistance in triaging and investigating the incident further. Darktrace’s SOC team conducted an in-depth investigation, enabling the customer to identify the exact moment of the file download, as well as the contents of the stolen documents. The customer later confirmed that the downloaded files contained sensitive corporate data, including customer details and payment information, likely intended for reuse or sharing with a new employer.
In this particular instance, Darktrace’s Autonomous Response capability was not active, allowing the malicious insider to successfully exfiltrate the files. If Autonomous Response had been enabled, Darktrace would have immediately acted upon detecting the login from an unusual (in this case 100% rare) location by logging out and disabling the SaaS user. This would have provided the customer with the necessary time to review the activity and verify whether the user was authorized to access their SaaS environments.
Conclusion
Insider threats pose a significant challenge for traditional security tools as they involve internal users who are expected to access SaaS platforms. These insiders have preexisting knowledge of the environment, sensitive data, and how to make their activities appear normal, as seen in this case with the use of Google Workspace. This familiarity allows them to avoid having to use more easily detectable intrusion methods like phishing campaigns.
Darktrace’s anomaly detection capabilities, which focus on identifying unusual activity rather than relying on specific rules and signatures, enable it to effectively detect deviations from a user’s expected behavior. For instance, an unusual login from a new location, as in this example, can be flagged even if the subsequent malicious activity appears innocuous due to the use of a trusted application like Google Drive.
Credit to Vivek Rajan (Cyber Analyst) and Ryan Traill (Analyst Content Lead)
Get the latest insights on emerging cyber threats
Attackers are adapting, are you ready? This report explores the latest trends shaping the cybersecurity landscape and what defenders need to know in 2025.
Identity-based attacks: How attackers are bypassing traditional defenses
Zero-day exploitation: The rise of previously unknown vulnerabilities
AI-driven threats: How adversaries are leveraging AI to outmaneuver security controls
RansomHub Ransomware: investigación de Darktrace sobre la herramienta más nueva en ShadowSyndicate's Arsenal
What is ShadowSyndicate?
ShadowSyndicate, also known as Infra Storm, is a threat actor reportedly active since July 2022, working with various ransomware groups and affiliates of ransomware programs, such as Quantum, Nokoyawa, and ALPHV. This threat actor employs tools like Cobalt Strike, Sliver, IcedID, and Matanbuchus malware in its attacks. ShadowSyndicate utilizes the same SSH fingerprint (1ca4cbac895fc3bd12417b77fc6ed31d) on many of their servers—85 as of September 2023. At least 52 of these servers have been linked to the Cobalt Strike command and control (C2) framework [1].
What is RansomHub?
First observed following the FBI's takedown of ALPHV/BlackCat in December 2023, RansomHub quickly gained notoriety as a Ransomware-as-a-Service (RaaS) operator. RansomHub capitalized on the law enforcement’s disruption of the LockBit group’s operations in February 2024 to market themselves to potential affiliates who had previously relied on LockBit’s encryptors. RansomHub's success can be largely attributed to their aggressive recruitment on underground forums, leading to the absorption of ex-ALPHV and ex-LockBit affiliates. They were one of the most active ransomware operators in 2024, with approximately 500 victims reported since February, according to their Dedicated Leak Site (DLS) [2].
ShadowSyndicate and RansomHub
External researchers have reported that ShadowSyndicate had as many as seven different ransomware families in their arsenal between July 2022, and September 2023. Now, ShadowSyndicate appears to have added RansomHub’s their formidable stockpile, becoming an affiliate of the RaaS provider [1].
Darktrace’s analysis of ShadowSyndicate across its customer base indicates that the group has been leveraging RansomHub ransomware in multiple attacks in September and October 2024. ShadowSyndicate likely shifted to using RansomHub due to the lucrative rates offered by this RaaS provider, with affiliates receiving up to 90% of the ransom—significantly higher than the general market rate of 70-80% [3].
In many instances where encryption was observed, ransom notes with the naming pattern “README_[a-zA-Z0-9]{6}.txt” were written to affected devices. The content of these ransom notes threatened to release stolen confidential data via RansomHub’s DLS unless a ransom was paid. During these attacks, data exfiltration activity to external endpoints using the SSH protocol was observed. The external endpoints to which the data was transferred were found to coincide with servers previously associated with ShadowSyndicate activity.
Darktrace’s coverage of ShadowSyndicate and RansomHub
Darktrace’s Threat Research team identified high-confidence indicators of compromise (IoCs) linked to the ShadowSyndicate group deploying RansomHub. The investigation revealed four separate incidents impacting Darktrace customers across various sectors, including education, manufacturing, and social services. In the investigated cases, multiple stages of the kill chain were observed, starting with initial internal reconnaissance and leading to eventual file encryption and data exfiltration.
Attack Overview
Internal Reconnaissance
The first observed stage of ShadowSyndicate attacks involved devices making multiple internal connection attempts to other internal devices over key ports, suggesting network scanning and enumeration activity. In this initial phase of the attack, the threat actor gathers critical details and information by scanning the network for open ports that might be potentially exploitable. In cases observed by Darktrace affected devices were typically seen attempting to connect to other internal locations over TCP ports including 22, 445 and 3389.
C2 Communication and Data Exfiltration
In most of the RansomHub cases investigated by Darktrace, unusual connections to endpoints associated with Splashtop, a remote desktop access software, were observed briefly before outbound SSH connections were identified.
Following this, Darktrace detected outbound SSH connections to the external IP address 46.161.27[.]151 using WinSCP, an open-source SSH client for Windows used for secure file transfer. The Cybersecurity and Infrastructure Security Agency (CISA) identified this IP address as malicious and associated it with ShadowSyndicate’s C2 infrastructure [4]. During connections to this IP, multiple gigabytes of data were exfiltrated from customer networks via SSH.
Data exfiltration attempts were consistent across investigated cases; however, the method of egress varied from one attack to another, as one would expect with a RaaS strain being employed by different affiliates. In addition to transfers to ShadowSyndicate’s infrastructure, threat actors were also observed transferring data to the cloud storage and file transfer service, MEGA, via HTTP connections using the ‘rclone’ user agent – a command-line program used to manage files on cloud storage. In another case, data exfiltration activity occurred over port 443, utilizing SSL connections.
Lateral Movement
In investigated incidents, lateral movement activity began shortly after C2 communications were established. In one case, Darktrace identified the unusual use of a new administrative credential which was quickly followed up with multiple suspicious executable file writes to other internal devices on the network.
The filenames for this executable followed the regex naming convention “[a-zA-Z]{6}.exe”, with two observed examples being “bWqQUx.exe” and “sdtMfs.exe”.
Figure 1: Cyber AI Analyst Investigation Process for the SMB Writes of Suspicious Files to Multiple Devices' incident.
Additionally, script files such as “Defeat-Defender2.bat”, “Share.bat”, and “def.bat” were also seen written over SMB, suggesting that threat actors were trying to evade network defenses and detection by antivirus software like Microsoft Defender.
File Encryption
Among the three cases where file encryption activity was observed, file names were changed by adding an extension following the regex format “.[a-zA-Z0-9]{6}”. Ransom notes with a similar naming convention, “README_[a-zA-Z0-9]{6}.txt”, were written to each share. While the content of the ransom notes differed slightly in each case, most contained similar text. Clear indicators in the body of the ransom notes pointed to the use of RansomHub ransomware in these attacks. As is increasingly the case, threat actors employed double extortion tactics, threatening to leak confidential data if the ransom was not paid. Like most ransomware, RansomHub included TOR site links for communication between its "customer service team" and the target.
Figure 2: The graph shows the behavior of a device with encryption activity, using the “SMB Sustained Mimetype Conversion” and “Unusual Activity Events” metrics over three weeks.
Since Darktrace’s Autonomous Response capability was not enabled during the compromise, the ransomware attack succeeded in its objective. However, Darktrace’s Cyber AI Analyst provided comprehensive coverage of the kill chain, enabling the customer to quickly identify affected devices and initiate remediation.
Figure 3: Cyber AI Analyst panel showing the critical incidents of the affected device from one of the cases investigated.
In lieu of Autonomous Response being active on the networks, Darktrace was able to suggest a variety of manual response actions intended to contain the compromise and prevent further malicious activity. Had Autonomous Response been enabled at the time of the attack, these actions would have been quickly applied without any human interaction, potentially halting the ransomware attack earlier in the kill chain.
Figure 4: A list of suggested Autonomous Response actions on the affected devices."
Conclusion
The Darktrace Threat Research team has noted a surge in attacks by the ShadowSyndicate group using RansomHub’s RaaS of late. RaaS has become increasingly popular across the threat landscape due to its ease of access to malware and script execution. As more individual threat actors adopt RaaS, security teams are struggling to defend against the increasing number of opportunistic attacks.
For customers subscribed to Darktrace’s Security Operations Center (SOC) services, the Analyst team promptly investigated detections of the aforementioned unusual and anomalous activities in the initial infection phases. Multiple alerts were raised via Darktrace’s Managed Threat Detection to warn customers of active ransomware incidents. By emphasizing anomaly-based detection and response, Darktrace can effectively identify devices affected by ransomware and take action against emerging activity, minimizing disruption and impact on customer networks.
Credit to Kwa Qing Hong (Senior Cyber Analyst and Deputy Analyst Team Lead, Singapore) and Signe Zahark (Principal Cyber Analyst, Japan)
Get the latest insights on emerging cyber threats
Attackers are adapting, are you ready? This report explores the latest trends shaping the cybersecurity landscape and what defenders need to know in 2025.
Identity-based attacks: How attackers are bypassing traditional defenses
Zero-day exploitation: The rise of previously unknown vulnerabilities
AI-driven threats: How adversaries are leveraging AI to outmaneuver security controls
