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Ransomware

Protecting Healthcare Organizations from Maze Ransomware

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21
Oct 2020
21
Oct 2020
Discover how Darktrace detected and protected a healthcare organization from a Maze ransomware attack. Stay informed and protect your data today.

Ransomware, with more severe consequences and against increasingly high-stakes targets, continues to cause chaos and disruption to organizations globally. Earlier this year saw a surge in a strain of ransomware known as ‘Maze’, which shut down operations at leading optical products provider Canon and wreaked havoc in Fortune 500 companies like Cognizant.

Ransomware targeting healthcare

Just last month, news of a woman in Germany dying after a ransomware attack on the Dusseldorf University Hospital hit the headlines, confirming that the threat to people is no longer theoretical.

Ransomware affects all industries but 2020 has seen cyber-criminals increasingly hit essential services like healthcare, local government and critical infrastructure – intentionally or as collateral damage. As the stakes rise, so too does the need to understand how to prevent these devastating and pervasive attacks.

Once deployed, ransomware can spread laterally through an organization’s digital infrastructure in seconds, taking entire systems offline in minutes. Attackers often strike at night or at weekends, when they know security teams’ response time will be slower. Machine-speed attacks require machine-speed defenses that can detect and respond to this threat without human guidance, and autonomously block the threat.

This blog explains how AI detects and stops ransomware by learning ‘normal’ across the digital estate – from email and SaaS applications to the network, cloud, IoT and industrial control systems – by looking at an example of a Maze ransomware attack caught by Darktrace in a customer’s environment.

Darktrace’s Immune System detected the threat as soon as it emerged, but as the Autonomous Response capability was configured in passive mode, neutralizing the threat still required human action. This means that attackers were able to move laterally across the organization at speed and began to encrypt files before the security team stepped in. In active mode, Antigena Network would have contained the activity in its earliest stages.

How does Darktrace detect ransomware like Maze?

As soon as Darktrace is deployed – whether virtually or on-premise – the AI begins to learn the ‘pattern of life’ for every user and device across the organization. This enables the technology to detect anomalous activity indicative of a cyber-threat. It does this without relying on hard-coded rules and signatures; an approach that requires a ‘Patient Zero’ before updating these lists and containing subsequent identical threats. When it comes to a novel instance of ransomware spreading across an organization and infecting hundreds of devices in seconds, such an approach becomes useless.

With an understanding of the organization’s ‘pattern of life’, Darktrace’s AI recognizes unusual activity in real time. Such activity might include:

ActivityDarktrace detectionsUnusual downloads from C2 serversEXE from Rare Destination / Masqueraded File TransferBrute forcing publicly accessible RDP serversIncoming RDP brute force modelsBrute forcing access to web portal user accounts with weak passwords or lacking MFAVarious brute force modelsC2 via Cobalt Strike / Empire PowershellSSL Beaconing to Rare Endpoint / Empire Powershell and Cobalt Strike modelsNetwork scanning for reconnaissance & EternalBlue exploitSuspicious Network Scan model known to download Advanced IP Scanner after successful exploitMimikatz usage for privilege escalationUnusual Admin SMB Session / Unusual RDP Admin Session (Procdump, PingCastle, and Bloodhound)Psexec / ‘Living off the Land’ for lateral movementUnusual Remote Command Execution / Unusual PSexec / Unusual DCE RPCData exfiltration to C2 serversData Sent to Rare Domain / Unusual Internal Download / Unusual External UploadEncryptionSuspicious SMB Activity / Additional File Extensions AppendedExfiltration of passwords through various cloud storage servicesData Sent to New External DomainRDP tunnels using NgrokOutbound RDP / Various beaconing models

In addition, Darktrace is able to identify attempts to brute force access on Internet-facing servers. It can also detect specific searches for passwords stored in plain text as well as various password manager databases.

Maze ransomware analysis

Figure 1: A timeline of the attack

Most recently, Darktrace’s AI detected a case of Maze ransomware targeting a healthcare organization. Darktrace’s Immune System spotted every stage of the attack lifecycle within seconds, and the Cyber AI Analyst immediately launched an automated investigation of the full incident, surfacing a natural-language, actionable summary for the security team.

The initial infection vector was spear phishing. Maze is frequently delivered to healthcare organizations using pandemic-themed phishing emails. Darktrace also offers AI-powered email security that understands normal behavior for every Microsoft 365 user and spots anomalies that are indicative of phishing, but in the absence of this protection, the emails were waved through by traditional gateways.

The attacker began engaging in network scanning activity and enumeration to escalate access within the Research and Development subnet. Darktrace’s AI detected a successful compromise of admin level credentials, unusual RDP activities and multiple Kerberos authentication attempts.

Darktrace detected the attacker uploading a domain controller, before batch files were written to multiple file shares, which were used for the encryption process.

An infected device then connected to a suspicious domain that is associated to Maze mazedecrypt[.]top and the TOR browser bundle was downloaded, likely for C2 purposes. A large volume of sensitive data from the R&D subnet was then uploaded to a rare domain. This is typical of Maze ransomware, which is seen as a ‘double threat’ in that it not only seeks to encrypt critical files but also sends a copy of them back to the attacker.

This form of attack, also known as doxware, then provides the attacker with leverage in the possible event that the organization refused to pay the ransom – they can sell the data on the Dark Web, or threaten to leak intellectual property to competitors, for instance.

Real-time automated investigations with Cyber AI Analyst

Throughout the attack lifecycle, multiple high-fidelity alerts were generated by Darktrace AI and this prompted the Cyber AI Analyst to automatically launch an investigation in the background, stitching together the different events into a single, comprehensive security incident, which it then displayed for human review in a single screen.

Figure 2: The data exfiltration to a rare external domain

Figure 3: Darktrace’s user interface highlighting the unusual activity and model breaches on a domain controller directly linked with the ransomware attack

Targeted, double-threat attacks like Maze ransomware are on the rise and extremely dangerous – and they are increasingly targeting high-stakes environments. Thousands of organizations are turning to AI, not only to detect and investigate on ransomware intrusions as demonstrated above, but to autonomously respond to events as they occur. Ransomware attacks like these show organizations why autonomous response in active mode is not just a nice to have – but necessary – as fast-moving threats demand machine-speed responses.

In a previous blog, we looked at a novel zero-day ransomware attack that slipped through legacy security tools – but Antigena Network was configured in active mode, autonomously stopping the threat in its tracks. This unique capability is becoming crucial for organizations in every industry who find themselves targeted by increasingly sophisticated attack methods.

Thanks to Darktrace analyst Adam Stevens for his insights on the above threat find.

Learn more about Autonomous Response

Darktrace model detections

  • Device / Suspicious Network Scan Activity
  • Device / Network Scan
  • Device / ICMP Address Scan
  • Unusual Activity / Unusual Internal Connections
  • Device / Multiple Lateral Movement Model Breaches
  • Experimental / Executable Uploaded to DC
  • Compromise / Ransomware::Suspicious SMB Activity
  • Compromise / Ransomware::Ransom or Offensive Words Written to SMB
  • Compliance / SMB Drive Write
  • Compliance / High Priority Compliance Model Breach
  • Anomalous Connection / SMB Enumeration
  • Device / Suspicious File Writes to Multiple Hidden SMB Shares
  • Device / New or Unusual Remote Command Execution
  • Anomalous Connection / New or Uncommon Service Control
  • Anomalous Connection / SMB Enumeration
  • Experimental / Possible RPC Execution
  • Anomalous Connection / High Volume of New or Uncommon Service Control
  • Experimental / Possible Ransom Note
  • Anomalous File / Internal::Additional Extension Appended to SMB File
  • Compliance / Tor Package Download
  • Device / Suspicious Domain
  • Device / Long Agent Connection to New Endpoint
  • Anomalous Connection / Data Sent to Rare Domain

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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ABOUT ThE AUTHOR
Max Heinemeyer
Chief Product Officer

Max is a cyber security expert with over a decade of experience in the field, specializing in a wide range of areas such as Penetration Testing, Red-Teaming, SIEM and SOC consulting and hunting Advanced Persistent Threat (APT) groups. At Darktrace, Max is closely involved with Darktrace’s strategic customers & prospects. He works with the R&D team at Darktrace, shaping research into new AI innovations and their various defensive and offensive applications. Max’s insights are regularly featured in international media outlets such as the BBC, Forbes and WIRED. Max holds an MSc from the University of Duisburg-Essen and a BSc from the Cooperative State University Stuttgart in International Business Information Systems.

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Thought Leadership

The State of AI in Cybersecurity: Understanding AI Technologies

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24
Jul 2024

About the State of AI Cybersecurity Report

Darktrace surveyed 1,800 CISOs, security leaders, administrators, and practitioners from industries around the globe. Our research was conducted to understand how the adoption of new AI-powered offensive and defensive cybersecurity technologies are being managed by organizations.

This blog continues the conversation from “The State of AI in Cybersecurity: Unveiling Global Insights from 1,800 Security Practitioners”. This blog will focus on security professionals’ understanding of AI technologies in cybersecurity tools.

To access download the full report, click here.

How familiar are security professionals with supervised machine learning

Just 31% of security professionals report that they are “very familiar” with supervised machine learning.

Many participants admitted unfamiliarity with various AI types. Less than one-third felt "very familiar" with the technologies surveyed: only 31% with supervised machine learning and 28% with natural language processing (NLP).

Most participants were "somewhat" familiar, ranging from 46% for supervised machine learning to 36% for generative adversarial networks (GANs). Executives and those in larger organizations reported the highest familiarity.

Combining "very" and "somewhat" familiar responses, 77% had familiarity with supervised machine learning, 74% generative AI, and 73% NLP. With generative AI getting so much media attention, and NLP being the broader area of AI that encompasses generative AI, these results may indicate that stakeholders are understanding the topic on the basis of buzz, not hands-on work with the technologies.  

If defenders hope to get ahead of attackers, they will need to go beyond supervised learning algorithms trained on known attack patterns and generative AI. Instead, they’ll need to adopt a comprehensive toolkit comprised of multiple, varied AI approaches—including unsupervised algorithms that continuously learn from an organization’s specific data rather than relying on big data generalizations.  

Different types of AI

Different types of AI have different strengths and use cases in cyber security. It’s important to choose the right technique for what you’re trying to achieve.  

Supervised machine learning: Applied more often than any other type of AI in cyber security. Trained on human attack patterns and historical threat intelligence.  

Large language models (LLMs): Applies deep learning models trained on extremely large data sets to understand, summarize, and generate new content. Used in generative AI tools.  

Natural language processing (NLP): Applies computational techniques to process and understand human language.  

Unsupervised machine learning: Continuously learns from raw, unstructured data to identify deviations that represent true anomalies.  

What impact will generative AI have on the cybersecurity field?

More than half of security professionals (57%) believe that generative AI will have a bigger impact on their field over the next few years than other types of AI.

Chart showing the types of AI expected to impact security the most
Figure 1: Chart from Darktrace's State of AI in Cybersecurity Report

Security stakeholders are highly aware of generative AI and LLMs, viewing them as pivotal to the field's future. Generative AI excels at abstracting information, automating tasks, and facilitating human-computer interaction. However, LLMs can "hallucinate" due to training data errors and are vulnerable to prompt injection attacks. Despite improvements in securing LLMs, the best cyber defenses use a mix of AI types for enhanced accuracy and capability.

AI education is crucial as industry expectations for generative AI grow. Leaders and practitioners need to understand where and how to use AI while managing risks. As they learn more, there will be a shift from generative AI to broader AI applications.

Do security professionals fully understand the different types of AI in security products?

Only 26% of security professionals report a full understanding of the different types of AI in use within security products.

Confusion is prevalent in today’s marketplace. Our survey found that only 26% of respondents fully understand the AI types in their security stack, while 31% are unsure or confused by vendor claims. Nearly 65% believe generative AI is mainly used in cybersecurity, though it’s only useful for identifying phishing emails. This highlights a gap between user expectations and vendor delivery, with too much focus on generative AI.

Key findings include:

  • Executives and managers report higher understanding than practitioners.
  • Larger organizations have better understanding due to greater specialization.

As AI evolves, vendors are rapidly introducing new solutions faster than practitioners can learn to use them. There's a strong need for greater vendor transparency and more education for users to maximize the technology's value.

To help ease confusion around AI technologies in cybersecurity, Darktrace has released the CISO’s Guide to Cyber AI. A comprehensive white paper that categorizes the different applications of AI in cybersecurity. Download the White Paper here.  

Do security professionals believe generative AI alone is enough to stop zero-day threats?

No! 86% of survey participants believe generative AI alone is NOT enough to stop zero-day threats

This consensus spans all geographies, organization sizes, and roles, though executives are slightly less likely to agree. Asia-Pacific participants agree more, while U.S. participants agree less.

Despite expecting generative AI to have the most impact, respondents recognize its limited security use cases and its need to work alongside other AI types. This highlights the necessity for vendor transparency and varied AI approaches for effective security across threat prevention, detection, and response.

Stakeholders must understand how AI solutions work to ensure they offer advanced, rather than outdated, threat detection methods. The survey shows awareness that old methods are insufficient.

To access the full report, click here.

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Inside the SOC

Jupyter Ascending: Darktrace’s Investigation of the Adaptive Jupyter Information Stealer

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18
Jul 2024

What is Malware as a Service (MaaS)?

Malware as a Service (MaaS) is a model where cybercriminals develop and sell or lease malware to other attackers.

This approach allows individuals or groups with limited technical skills to launch sophisticated cyberattacks by purchasing or renting malware tools and services. MaaS is often provided through online marketplaces on the dark web, where sellers offer various types of malware, including ransomware, spyware, and trojans, along with support services such as updates and customer support.

The Growing MaaS Marketplace

The Malware-as-a-Service (MaaS) marketplace is rapidly expanding, with new strains of malware being regularly introduced and attracting waves of new and previous attackers. The low barrier for entry, combined with the subscription-like accessibility and lucrative business model, has made MaaS a prevalent tool for cybercriminals. As a result, MaaS has become a significant concern for organizations and their security teams, necessitating heightened vigilance and advanced defense strategies.

Examples of Malware as a Service

  • Ransomware as a Service (RaaS): Providers offer ransomware kits that allow users to launch ransomware attacks and share the ransom payments with the service provider.
  • Phishing as a Service: Services that provide phishing kits, including templates and email lists, to facilitate phishing campaigns.
  • Botnet as a Service: Renting out botnets to perform distributed denial-of-service (DDoS) attacks or other malicious activities.
  • Information Stealer: Information stealers are a type of malware specifically designed to collect sensitive data from infected systems, such as login credentials, credit card numbers, personal identification information, and other valuable data.

How does information stealer malware work?

Information stealers are an often-discussed type MaaS tool used to harvest personal and proprietary information such as administrative credentials, banking information, and cryptocurrency wallet details. This information is then exfiltrated from target networks via command-and-control (C2) communication, allowing threat actors to monetize the data. Information stealers have also increasingly been used as an initial access vector for high impact breaches including ransomware attacks, employing both double and triple extortion tactics.

After investigating several prominent information stealers in recent years, the Darktrace Threat Research team launched an investigation into indicators of compromise (IoCs) associated with another variant in late 2023, namely the Jupyter information stealer.

What is Jupyter information stealer and how does it work?

The Jupyter information stealer (also known as Yellow Cockatoo, SolarMarker, and Polazert) was first observed in the wild in late 2020. Multiple variants have since become part of the wider threat landscape, however, towards the end of 2023 a new variant was observed. This latest variant achieved greater stealth and updated its delivery method, targeting browser extensions such as Edge, Firefox, and Chrome via search engine optimization (SEO) poisoning and malvertising. This then redirects users to download malicious files that typically impersonate legitimate software, and finally initiates the infection and the attack chain for Jupyter [3][4]. In recently noted cases, users download malicious executables for Jupyter via installer packages created using InnoSetup – an open-source compiler used to create installation packages in the Windows OS.

The latest release of Jupyter reportedly takes advantage of signed digital certificates to add credibility to downloaded executables, further supplementing its already existing tactics, techniques and procedures (TTPs) for detection evasion and sophistication [4]. Jupyter does this while still maintaining features observed in other iterations, such as dropping files into the %TEMP% folder of a system and using PowerShell to decrypt and load content into memory [4]. Another reported feature includes backdoor functionality such as:

  • C2 infrastructure
  • Ability to download and execute malware
  • Execution of PowerShell scripts and commands
  • Injecting shellcode into legitimate windows applications

Darktrace Coverage of Jupyter information stealer

In September 2023, Darktrace’s Threat Research team first investigated Jupyter and discovered multiple IoCs and TTPs associated with the info-stealer across the customer base. Across most investigated networks during this time, Darktrace observed the following activity:

  • HTTP POST requests over destination port 80 to rare external IP addresses (some of these connections were also made via port 8089 and 8090 with no prior hostname lookup).
  • HTTP POST requests specifically to the root directory of a rare external endpoint.
  • Data streams being sent to unusual external endpoints
  • Anomalous PowerShell execution was observed on numerous affected networks.

Taking a further look at the activity patterns detected, Darktrace identified a series of HTTP POST requests within one customer’s environment on December 7, 2023. The HTTP POST requests were made to the root directory of an external IP address, namely 146.70.71[.]135, which had never previously been observed on the network. This IP address was later reported to be malicious and associated with Jupyter (SolarMarker) by open-source intelligence (OSINT) [5].

Device Event Log indicating several connections from the source device to the rare external IP address 146.70.71[.]135 over port 80.
Figure 1: Device Event Log indicating several connections from the source device to the rare external IP address 146.70.71[.]135 over port 80.

This activity triggered the Darktrace / NETWORK model, ‘Anomalous Connection / Posting HTTP to IP Without Hostname’. This model alerts for devices that have been seen posting data out of the network to rare external endpoints without a hostname. Further investigation into the offending device revealed a significant increase in external data transfers around the time Darktrace alerted the activity.

This External Data Transfer graph demonstrates a spike in external data transfer from the internal device indicated at the top of the graph on December 7, 2023, with a time lapse shown of one week prior.
Figure 2: This External Data Transfer graph demonstrates a spike in external data transfer from the internal device indicated at the top of the graph on December 7, 2023, with a time lapse shown of one week prior.

Packet capture (PCAP) analysis of this activity also demonstrates possible external data transfer, with the device observed making a POST request to the root directory of the malicious endpoint, 146.70.71[.]135.

PCAP of a HTTP POST request showing streams of data being sent to the endpoint, 146.70.71[.]135.
Figure 3: PCAP of a HTTP POST request showing streams of data being sent to the endpoint, 146.70.71[.]135.

In other cases investigated by the Darktrace Threat Research team, connections to the rare external endpoint 67.43.235[.]218 were detected on port 8089 and 8090. This endpoint was also linked to Jupyter information stealer by OSINT sources [6].

Darktrace recognized that such suspicious connections represented unusual activity and raised several model alerts on multiple customer environments, including ‘Compromise / Large Number of Suspicious Successful Connections’ and ‘Anomalous Connection / Multiple Connections to New External TCP Port’.

In one instance, a device that was observed performing many suspicious connections to 67.43.235[.]218 was later observed making suspicious HTTP POST connections to other malicious IP addresses. This included 2.58.14[.]246, 91.206.178[.]109, and 78.135.73[.]176, all of which had been linked to Jupyter information stealer by OSINT sources [7] [8] [9].

Darktrace further observed activity likely indicative of data streams being exfiltrated to Jupyter information stealer C2 endpoints.

Graph displaying the significant increase in the number of HTTP POST requests with No Get made by an affected device, likely indicative of Jupyter information stealer C2 activity.
Figure 4: Graph displaying the significant increase in the number of HTTP POST requests with No Get made by an affected device, likely indicative of Jupyter information stealer C2 activity.

In several cases, Darktrace was able to leverage customer integrations with other security vendors to add additional context to its own model alerts. For example, numerous customers who had integrated Darktrace with Microsoft Defender received security integration alerts that enriched Darktrace’s model alerts with additional intelligence, linking suspicious activity to Jupyter information stealer actors.

The security integration model alerts ‘Security Integration / Low Severity Integration Detection’ and (right image) ‘Security Integration / High Severity Integration Detection’, linking suspicious activity observed by Darktrace with Jupyter information stealer (SolarMarker).
Figure 5: The security integration model alerts ‘Security Integration / Low Severity Integration Detection’ and (right image) ‘Security Integration / High Severity Integration Detection’, linking suspicious activity observed by Darktrace with Jupyter information stealer (SolarMarker).

Conclusion

The MaaS ecosystems continue to dominate the current threat landscape and the increasing sophistication of MaaS variants, featuring advanced defense evasion techniques, poses significant risks once deployed on target networks.

Leveraging anomaly-based detections is crucial for staying ahead of evolving MaaS threats like Jupyter information stealer. By adopting AI-driven security tools like Darktrace / NETWORK, organizations can more quickly identify and effectively detect and respond to potential threats as soon as they emerge. This is especially crucial given the rise of stealthy information stealing malware strains like Jupyter which cannot only harvest and steal sensitive data, but also serve as a gateway to potentially disruptive ransomware attacks.

Credit to Nahisha Nobregas (Senior Cyber Analyst), Vivek Rajan (Cyber Analyst)

References

1.     https://www.paloaltonetworks.com/cyberpedia/what-is-multi-extortion-ransomware

2.     https://flashpoint.io/blog/evolution-stealer-malware/

3.     https://blogs.vmware.com/security/2023/11/jupyter-rising-an-update-on-jupyter-infostealer.html

4.     https://www.morphisec.com/hubfs/eBooks_and_Whitepapers/Jupyter%20Infostealer%20WEB.pdf

5.     https://www.virustotal.com/gui/ip-address/146.70.71.135

6.     https://www.virustotal.com/gui/ip-address/67.43.235.218/community

7.     https://www.virustotal.com/gui/ip-address/2.58.14.246/community

8.     https://www.virustotal.com/gui/ip-address/91.206.178.109/community

9.     https://www.virustotal.com/gui/ip-address/78.135.73.176/community

Appendices

Darktrace Model Detections

  • Anomalous Connection / Posting HTTP to IP Without Hostname
  • Compromise / HTTP Beaconing to Rare Destination
  • Unusual Activity / Unusual External Data to New Endpoints
  • Compromise / Slow Beaconing Activity To External Rare
  • Compromise / Large Number of Suspicious Successful Connections
  • Anomalous Connection / Multiple Failed Connections to Rare Endpoint
  • Compromise / Excessive Posts to Root
  • Compromise / Sustained SSL or HTTP Increase
  • Security Integration / High Severity Integration Detection
  • Security Integration / Low Severity Integration Detection
  • Anomalous Connection / Multiple Connections to New External TCP Port
  • Unusual Activity / Unusual External Data Transfer

AI Analyst Incidents:

  • Unusual Repeated Connections
  • Possible HTTP Command and Control to Multiple Endpoints
  • Possible HTTP Command and Control

List of IoCs

Indicators – Type – Description

146.70.71[.]135

IP Address

Jupyter info-stealer C2 Endpoint

91.206.178[.]109

IP Address

Jupyter info-stealer C2 Endpoint

146.70.92[.]153

IP Address

Jupyter info-stealer C2 Endpoint

2.58.14[.]246

IP Address

Jupyter info-stealer C2 Endpoint

78.135.73[.]176

IP Address

Jupyter info-stealer C2 Endpoint

217.138.215[.]105

IP Address

Jupyter info-stealer C2 Endpoint

185.243.115[.]88

IP Address

Jupyter info-stealer C2 Endpoint

146.70.80[.]66

IP Address

Jupyter info-stealer C2 Endpoint

23.29.115[.]186

IP Address

Jupyter info-stealer C2 Endpoint

67.43.235[.]218

IP Address

Jupyter info-stealer C2 Endpoint

217.138.215[.]85

IP Address

Jupyter info-stealer C2 Endpoint

193.29.104[.]25

IP Address

Jupyter info-stealer C2 Endpoint

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About the author
Nahisha Nobregas
SOC Analyst
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