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Cyber AI Analyst: Cutting Through the Noise to Gain the Security Edge
For cyber security experts, it’s hard enough staying on top of the latest threats and emerging attacks without having to deal with a virtual tsunami of alert noise from systems monitoring email, SaaS environments, and endpoints – in addition to IaaS cloud and on-premises networks. Unfortunately, fatigue from these demands can lead to overworking, burnout, and crucially, high employee turnover.
The worldwide industry shortage of 3.5 million cyber security professionals only exacerbates the problem. Not only does it add pressure to the current stock of skilled and available security professionals, but it also raises the stakes for CISOs and other security leaders to find a way to cut through the alert noise while staying on ahead of threat actors who never stop innovating and applying novel malware strains and attack techniques.
Working Smarter Not Harder
One way to help with retention is to empower security teams to break away from monotony and to think creatively and leverage their expertise where it can really add value. Working smarter, rather than harder, is often easier said than done, but by employing automation and AI-driven tools to take on the heavy lifting of threat detection, investigation, and response, human teams can be given the breathing room needed to focus on long-term objectives and think more deeply about their security approaches.
It is important for security programs to continuously level up alongside evolving threat landscapes by questioning existing security operations, and this cannot be achieved during times of hand-to-hand alert combat.
When alerts are fewer, higher quality, and context-heavy, the background to each can be easily explored, whether that’s reevaluating a policy or configuration, or simply asking useful questions around the company’s broader security approach. Work done at this level empowers security teams and fosters growth.
Less is More
Business risk– or the potential impact of cyber disruption– should be the number one concern driving a security team, but lack of resources is a near-constant constraint. Reducing the volume of alerts doesn’t just mean bringing the noise floor up. You can think of the noise floor as an alert threshold: if it is too high then there are fewer alerts, but more threats may be missed, whereas if it is too low, there are high volumes of unhelpful false positives. Freeing up time for the team must not equate to ignoring alerts; it should instead mean focusing on the alerts that matter.
Darktrace’s technologies make this possible, with Darktrace DETECT™ and Cyber AI Analyst working together to address alert fatigue and burnout for security teams while strengthening an organizations’ overall security posture. Cyber AI Analyst essentially takes over the busy work from the human analysts and elevates a team’s overall decision making. Teams now operate at higher levels, as they’re not stuck in mundane alert management and humans are brought in only after the machine and AI have done the heavy lifting.
“Before AI Analyst, we were barely treading water with all of the alerts, most of which were false positives, our old systems produced daily. With AI Analyst, we’ve been able to exponentially reduce those alerts, harden our environment, and get strategic.”
Dr. Robert Spangler, the CISO and Assistant Executive Director of the New Jersey State Bar Association.
Imagine a scenario in which Darktrace observed around 9.6 billion events over a 28-day period. DETECT and Cyber AI Analyst might distill that huge amount of data down into just, say, 54 critical incidents, or just two per day. Here’s how:
9.6 billion events
When trying to understand the full picture, every single puzzle piece counts. That’s why Darktrace’s Self-Learning AI goes wherever your organization has data, integrating with data sources across the digital estate, including network, email, endpoints, OT, cloud, and SaaS environments. And with an open architecture, Darktrace facilitates quick and easy integrations with everything from SIEMs and SOARs to public clouds and the latest Zero Trust technologies. So, any data can become learnable, whether directly ingested or via integration.
By examining this full and contextualized data set, Self-Learning AI builds a constantly evolving understanding of what ‘normal’ looks like for the entire organization. Every connection, every email, app login, resource accessed, VM spun up, PLC reprogrammed, and more become signals from which Darktrace can learn, evaluate, and improve its understanding.
40,404 model breaches
The billions of events are analyzed by Darktrace DETECT, which uses its extensive knowledge of ‘normal’ to draw out hosts of subtle anomalies or ‘AI model breaches.’ Many of these AI model breaches will be weak indicators of threatening activity, and most will not be sufficient to individually signal a threat. For that reason, no human attention is required at this stage. Darktrace DETECT will continue to draw anomalous behaviors from the ongoing stream of events without the need for intervention.
200 incidents
The Cyber AI Analyst takes the total list of model breaches collated by DETECT and performs the truly sophisticated work of determining distinct threat incidents. By piecing together anomalies which may, in themselves, appear harmless, the AI Analyst draws out subtle and often wide-ranging attacks, tracking their route from the initial compromise to the present moment. This creates a much shorter list of genuine threat incidents, but there is still no need for human attention at this stage.
54 critical incidents
Once it has discovered the threat incidents facing an organization, the Cyber AI Analyst begins the crucial processes of triage to determine which incidents need to be surfaced to the security team, and in what order of priority. This supplies the human team with a highly focused briefing of the most pressing threats, massively reducing their overall workload and minimizing or potentially eradicating alert fatigue. In the above example of a month with over 9.6 billion distinct events, the team are left with just two incidents to address per day. These two incidents are clearly presented with natural language-processing and all the most relevant info, including details, devices, and dates.
“When we had other, noisier systems, we didn’t have the time to have truly in-depth discussions or conduct deep investigations, so there were fewer teachable moments for junior team members and fewer opportunities to inform our cybersecurity strategy as a whole,” Spangler said. “Now, we’re not just a better team, we’re more efficient, responsive, and informed than we’ve ever been. We’re all better cyber security professionals as a result.”
In the event of a breach, CISOs and security leaders want the full incident report, and they want it yesterday. The promise of AI is to handle specific tasks at a speed and scale that humans can’t. Going from 9.6 billion events to 54 incidents demonstrates the scale, but it’s important to consider the impact of speed here as well, as the Cyber AI Analyst works in real time, meaning all relevant events are presented in an easy to consume downloadable report available immediately upon investigation.
This isn’t a black box either; every step of the AI Analyst’s investigation process is visible to the human team. Not only can they see the relevant events and breaches that led to the incident, but if required, they can pivot into them easily with a click. If the investigation requires going all the way down to the metadata level to easily peruse the filtered events of the 9.6 billion overall signals or even to PCAP data, those are available and easy to find too.
Since DETECT and Cyber AI Analyst not only reduce alert fatigue but also simplify incident investigations, security teams feel empowered and experience less burnout.
“We’ve been stable and have had minimal turnover since we started using AI Analyst,” Spangler said. “We’re not scrambling to keep up with noisy and time-consuming false positives, making the investigations that we undertake stimulating and– I say this cautiously– fun! Put simply, the thing we all love about this career, the virtual chess game we play with attackers, is a lot more fun when you know you’re going to win.”
Autonomous Response
Organizations that deploy Darktrace RESPOND™ can address the incidents raised by DETECT and the Cyber AI Analyst autonomously, and in mere seconds. Using the full context of the organization built up by Self-Learning AI, RESPOND takes the least disruptive measures necessary to disarm threats at machine speed. By the time the security team learns about the attack, it is already contained, continuing to save them from the hand-to-hand combat of threat fighting.
With day-to-day threat detection, response, and analysis taken care of, security teams are free to give full and sustained attention to their overall security posture. Neutralized threats may yet reveal broader security gaps and potential improvements which the team now has the time and headspace to pursue.
For example, discovering a trend that users are uploading potentially sensitive data via third-party file-sharing services might lead to a discussion about whether it should be company policy to block access to this service, reducing to zero the number of future alerts that would have been triggered by this behavior. Importantly, this wouldn’t be altering the aforementioned noise floor, but instead fundamentally altering security policies to align with the needs of the business, which could indirectly affect future alerting, as activities may subside.
As a result, practitioners find more value in their work, security teams efforts are optimized, and organizations are strengthened overall.
“We’re now focused on the items that AI Analyst alerts us to, which are always worth looking into because they either identify an activity that we need to get eyes on and/or provide us with insight into ways we can harden our network,” Spangler said. “The hardening that we’ve done has been incalculably beneficial– it’s one of the reasons we get fewer alerts, and it’s also protected us against a wide variety of threats.”
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Inside the SOC
PurpleFox in a Henhouse: How Darktrace Hunted Down a Persistent and Dynamic Rootkit
Versatile Malware: PurpleFox
As organizations and security teams across the world move to bolster their digital defenses against cyber threats, threats actors, in turn, are forced to adopt more sophisticated tactics, techniques and procedures (TTPs) to circumvent them. Rather than being static and predictable, malware strains are becoming increasingly versatile and therefore elusive to traditional security tools.
One such example is PurpleFox. First observed in 2018, PurpleFox is a combined fileless rootkit and backdoor trojan known to target Windows machines. PurpleFox is known for consistently adapting its functionalities over time, utilizing different infection vectors including known vulnerabilities (CVEs), fake Telegram installers, and phishing. It is also leveraged by other campaigns to deliver ransomware tools, spyware, and cryptocurrency mining malware. It is also widely known for using Microsoft Software Installer (MSI) files masquerading as other file types.
The Evolution of PurpleFox
The Original Strain
First reported in March 2018, PurpleFox was identified to be a trojan that drops itself onto Windows machines using an MSI installation package that alters registry values to replace a legitimate Windows system file [1]. The initial stage of infection relied on the third-party toolkit RIG Exploit Kit (EK). RIG EK is hosted on compromised or malicious websites and is dropped onto the unsuspecting system when they visit browse that site. The built-in Windows installer (MSIEXEC) is leveraged to run the installation package retrieved from the website. This, in turn, drops two files into the Windows directory – namely a malicious dynamic-link library (DLL) that acts as a loader, and the payload of the malware. After infection, PurpleFox is often used to retrieve and deploy other types of malware.
Subsequent Variants
Since its initial discovery, PurpleFox has also been observed leveraging PowerShell to enable fileless infection and additional privilege escalation vulnerabilities to increase the likelihood of successful infection [2]. The PowerShell script had also been reported to be masquerading as a .jpg image file. PowerSploit modules are utilized to gain elevated privileges if the current user lacks administrator privileges. Once obtained, the script proceeds to retrieve and execute a malicious MSI package, also masquerading as an image file. As of 2020, PurpleFox no longer relied on the RIG EK for its delivery phase, instead spreading via the exploitation of the SMB protocol [3]. The malware would leverage the compromised systems as hosts for the PurpleFox payloads to facilitate its spread to other systems. This mode of infection can occur without any user action, akin to a worm.
The current iteration of PurpleFox reportedly uses brute-forcing of vulnerable services, such as SMB, to facilitate its spread over the network and escalate privileges. By scanning internet-facing Windows computers, PurpleFox exploits weak passwords for Windows user accounts through SMB, including administrative credentials to facilitate further privilege escalation.
Darktrace detection of PurpleFox
In July 2023, Darktrace observed an example of a PurpleFox infection on the network of a customer in the healthcare sector. This observation was a slightly different method of downloading the PurpleFox payload. An affected device was observed initiating a series of service control requests using DCE-RPC, instructing the device to make connections to a host of servers to download a malicious .PNG file, later confirmed to be the PurpleFox rootkit. The device was then observed carrying out worm-like activity to other external internet-facing servers, as well as scanning related subnets.
Darktrace DETECT™ was able to successfully identify and track this compromise across the cyber kill chain and ensure the customer was able to take swift remedial action to prevent the attack from escalating further.
While the customer in question did have Darktrace RESPOND™, it was configured in human confirmation mode, meaning any mitigative actions had to be manually applied by the customer’s security team. If RESPOND had been enabled in autonomous response mode at the time of the attack, it would have been able to take swift action against the compromise to contain it at the earliest instance.
Attack Overview
Initial Scanning over SMB
On July 14, 2023, Darktrace detected the affected device scanning other internal devices on the customer’s network via port 445. The numerous connections were consistent with the aforementioned worm-like activity that has been reported from PurpleFox behavior as it appears to be targeting SMB services looking for open or vulnerable channels to exploit.
This initial scanning activity was detected by Darktrace DETECT, specifically through the model breach ‘Device / Suspicious SMB Scanning Activity’. Darktrace’s Cyber AI Analyst™ then launched an autonomous investigation into these internal connections and tied them into one larger-scale network reconnaissance incident, rather than a series of isolated connections.
As Darktrace RESPOND was configured in human confirmation mode, it was unable to autonomously block these internal connections. However, it did suggest blocking connections on port 445, which could have been manually applied by the customer’s security team.
Privilege Escalation
The device successfully logged in via NTLM with the credential, ‘administrator’. Darktrace recognized that the endpoint was external to the customer’s environment, indicating that the affected device was now being used to propagate the malware to other networks. Considering the lack of observed brute-force activity up to this point, the credentials for ‘administrator’ had likely been compromised prior to Darktrace’s deployment on the network, or outside of Darktrace’s purview via a phishing attack.
Exploitation
Darktrace then detected a series of service control requests over DCE-RPC using the credential ‘admin’ to make SVCCTL Create Service W Requests. A script was then observed where the controlled device is instructed to launch mshta.exe, a Windows-native binary designed to execute Microsoft HTML Application (HTA) files. This enables the execution of arbitrary script code, VBScript in this case.
There are a few MSIEXEC flags to note:
- /i : installs or configures a product
- /Q : sets the user interface level. In this case, it is set to ‘No UI’, which is used for “quiet” execution, so no user interaction is required
Evidently, this was an attempt to evade detection by endpoint users as it is surreptitiously installed onto the system. This corresponds to the download of the rootkit that has previously been associated with PurpleFox. At this stage, the infected device continues to be leveraged as an attack device and scans SMB services over external endpoints. The device also appeared to attempt brute-forcing over NTLM using the same ‘administrator’ credential to these endpoints. This activity was identified by Darktrace DETECT which, if enabled in autonomous response mode would have instantly blocked similar outbound connections, thus preventing the spread of PurpleFox.
Installation
On August 9, Darktrace observed the device making initial attempts to download a malicious .PNG file. This was a notable change in tactics from previously reported PurpleFox campaigns which had been observed utilizing .MOE files for their payloads [3]. The .MOE payloads are binary files that are more easily detected and blocked by traditional signatured-based security measures as they are not associated with known software. The ubiquity of .PNG files, especially on the web, make identifying and blacklisting the files significantly more difficult.
The first connection was made with the URI ‘/test.png’. It was noted that the HTTP method here was HEAD, a method similar to GET requests except the server must not return a message-body in the response.
The metainformation contained in the HTTP headers in response to a HEAD request should be identical to the information sent in response to a GET request. This method is often used to test hypertext links for validity and recent modification. This is likely a way of checking if the server hosting the payload is still active. Avoiding connections that could possibly be detected by antivirus solutions can help keep this activity under-the-radar.
The server responds with a status code of 200 before the download begins. The HEAD request could be part of the attacker’s verification that the server is still running, and that the payload is available for download. The ‘/test.png’ HEAD request was sent twice, likely for double confirmation to begin the file transfer.
Subsequent analysis using a Packet Capture (PCAP) tool revealed that this connection used the Windows Installer user agent that has previously been associated with PurpleFox. The device then began to download a payload that was masquerading as a Microsoft Word document. The device was thus able to download the payload twice, from two separate endpoints.
By masquerading as a Microsoft Word file, the threat actor was likely attempting to evade the detection of the endpoint user and traditional security tools by passing off as an innocuous text document. Likewise, using a Windows Installer user agent would enable threat actors to bypass antivirus measures and disguise the malicious installation as legitimate download activity.
Darktrace DETECT identified that these were masqueraded file downloads by correctly identifying the mismatch between the file extension and the true file type. Subsequently, AI Analyst was able to correctly identify the file type and deduced that this download was indicative of the device having been compromised.
In this case, the device attempted to download the payload from several different endpoints, many of which had low antivirus detection rates or open-source intelligence (OSINT) flags, highlighting the need to move beyond traditional signature-base detections.
If Darktrace RESPOND was enabled in autonomous response mode at the time of the attack it would have acted by blocking connections to these suspicious endpoints, thus preventing the download of malicious files. However, as RESPOND was in human confirmation mode, RESPOND actions required manual application by the customer’s security team which unfortunately did not happen, as such the device was able to download the payloads.
Conclusion
The PurpleFox malware is a particularly dynamic strain known to continually evolve over time, utilizing a blend of old and new approaches to achieve its goals which is likely to muddy expectations on its behavior. By frequently employing new methods of attack, malicious actors are able to bypass traditional security tools that rely on signature-based detections and static lists of indictors of compromise (IoCs), necessitating a more sophisticated approach to threat detection.
Darktrace DETECT’s Self-Learning AI enables it to confront adaptable and elusive threats like PurpleFox. By learning and understanding customer networks, it is able to discern normal network behavior and patterns of life, distinguishing expected activity from potential deviations. This anomaly-based approach to threat detection allows Darktrace to detect cyber threats as soon as they emerge.
By combining DETECT with the autonomous response capabilities of RESPOND, Darktrace customers are able to effectively safeguard their digital environments and ensure that emerging threats can be identified and shut down at the earliest stage of the kill chain, regardless of the tactics employed by would-be attackers.
Credit to Piramol Krishnan, Cyber Analyst, Qing Hong Kwa, Senior Cyber Analyst & Deputy Team Lead, Singapore
Appendices
Darktrace Model Detections
- Device / Increased External Connectivity
- Device / Large Number of Connections to New Endpoints
- Device / SMB Session Brute Force (Admin)
- Compliance / External Windows Communications
- Anomalous Connection / New or Uncommon Service Control
- Compromise / Unusual SVCCTL Activity
- Compromise / Rare Domain Pointing to Internal IP
- Anomalous File / Masqueraded File Transfer
RESPOND Models
- Antigena / Network / Significant Anomaly / Antigena Breaches Over Time Block
- Antigena / Network / External Threat / Antigena Suspicious Activity Block
- Antigena / Network / Significant Anomaly / Antigena Significant Anomaly from Client Block
- Antigena / Network / Significant Anomaly / Antigena Enhanced Monitoring from Client Block
- Antigena / Network / External Threat / Antigena Suspicious File Block
- Antigena / Network / External Threat / Antigena File then New Outbound Block
List of IoCs
IoC - Type - Description
/C558B828.Png - URI - URI for Purple Fox Rootkit [4]
5b1de649f2bc4eb08f1d83f7ea052de5b8fe141f - File Hash - SHA1 hash of C558B828.Png file (Malware payload)
190.4.210[.]242 - IP - Purple Fox C2 Servers
218.4.170[.]236 - IP - IP for download of .PNG file (Malware payload)
180.169.1[.]220 - IP - IP for download of .PNG file (Malware payload)
103.94.108[.]114:10837 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
221.199.171[.]174:16543 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
61.222.155[.]49:14098 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
178.128.103[.]246:17880 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
222.134.99[.]132:12539 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
164.90.152[.]252:18075 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
198.199.80[.]121:11490 - IP - IP from Service Control MSIEXEC script to download PNG file (Malware payload)
MITRE ATT&CK Mapping
Tactic - Technique
Reconnaissance - Active Scanning T1595, Active Scanning: Scanning IP Blocks T1595.001, Active Scanning: Vulnerability Scanning T1595.002
Resource Development - Obtain Capabilities: Malware T1588.001
Initial Access, Defense Evasion, Persistence, Privilege Escalation - Valid Accounts: Default Accounts T1078.001
Initial Access - Drive-by Compromise T1189
Defense Evasion - Masquerading T1036
Credential Access - Brute Force T1110
Discovery - Network Service Discovery T1046
Command and Control - Proxy: External Proxy T1090.002
References
- https://blog.360totalsecurity.com/en/purple-fox-trojan-burst-out-globally-and-infected-more-than-30000-users/
- https://www.trendmicro.com/en_us/research/19/i/purple-fox-fileless-malware-with-rookit-component-delivered-by-rig-exploit-kit-now-abuses-powershell.html
- https://www.akamai.com/blog/security/purple-fox-rootkit-now-propagates-as-a-worm
- https://www.foregenix.com/blog/an-overview-on-purple-fox
- https://www.trendmicro.com/en_sg/research/21/j/purplefox-adds-new-backdoor-that-uses-websockets.html
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OT
$70 Million in Cyber Security Funding for Electric Cooperatives & Utilities
What is the Bipartisan Infrastructure Deal?
The Bipartisan Infrastructure Law passed by congress in 2021 aimed to upgrade power and infrastructure to deliver clean, reliable energy across the US to achieve zero-emissions. To date, the largest investment in clean energy, the deal will fund new programs to support the development and deployment of clean energy technology.
Why is it relevant to electric municipalities?
Section 40124 of the Bipartisan Infrastructure Law allocates $250 million over a 5-year period to create the Rural and Municipal Utility Cybersecurity (RMUC) Program to help electric cooperative, municipal, and small investor-owned utilities protect against, detect, respond to, and recover from cybersecurity threats.1 This act illuminates the value behind a full life-cycle approach to cyber security. Thus, finding a cyber security solution that can provide all aspects of security in one integrated platform would enhance the overall security posture and ease many of the challenges that arise with adopting multiple point solutions.
On November 16, 2023 the Office of Cybersecurity, Energy Security, and Emergency Response (CESER) released the Advanced Cybersecurity Technology (ACT) for electric utilities offering a $70 million funding opportunity that aims to enhance the cybersecurity posture of electric cooperative, municipal, and small investor-owned utilities.
Funding Details
10 projects will be funded with application submissions due November 29, 2023, 5:00 pm ET with $200,000 each in cash prizes in the following areas:
- Direct support for eligible utilities to make investments in cybersecurity technologies, tools, training, and improvements in utility processes and procedures;
- Funding to strengthen the peer-to-peer and not-for-profit cybersecurity technical assistance ecosystem currently serving eligible electric utilities; and
- Increasing access to cybersecurity technical assistance and training for eligible utilities with limited cybersecurity resources. 2
To submit for this award visit: https://www.herox.com/ACT1Prize
How can electric municipalities utilize the funding?
While the adoption of hybrid working patterns increase cloud and SaaS usage, the number of industrial IoT devices also continues to rise. The result is decrease in visibility for security teams and new entry points for attackers. Particularly for energy and utility organizations.
Electric cooperatives seeking to enhance their cyber security posture can aim to invest in cyber security tools that provide the following:
Compliance support: Consider finding an OT security solution that maps out how its solutions and features help your organization comply with relevant compliance mandates such as NIST, ISA, FERC, TSA, HIPAA, CIS Controls, and more.
Anomaly based detection: Siloed security solutions also fail to detect attacks that span
the entire organization. Anomaly-based detection enhances an organization’s cyber security posture by proactively defending against potential attacks and maintaining a comprehensive view of their attack surface.
Integration capabilities: Implementation of several point solutions that complete individual tasks runs the risk of increasing workloads for operators and creates additional challenges with compliance, budgeting, and technical support. Look for cyber security tools that integrate with your existing technologies.
Passive and active asset tracking: Active Identification offers accurate enumeration, real time updates, vulnerability assessment, asset validation while Passive Identification eliminates the risk of operational disruption, minimizes risk, does not generate additional network traffic. It would be ideal to find a security solution that can do both.
Can secure both IT and OT in unison: Given that most OT cyber-attacks actually start in IT networks before pivoting into OT, a mature security posture for critical infrastructure would include a single solution for both IT and OT. Separate solutions for IT and OT present challenges when defending network boundaries and detecting incidents when an attacker pivots from IT to OT. These independent solutions also significantly increase operator workload and materially diminish risk mitigation efforts.
Darktrace/OT for Electric Cooperatives and Utilities
For smaller teams with just one or two dedicated employees, Darktrace’s Cyber AI Analyst and Investigation features allow end users to spend less time in the platform as it compiles critical incidents into comprehensive actionable event reports. AI Analyst brings all the information into a centralized view with incident reporting in natural language summaries and can be generated for compliance reports specific to regulatory requirements.
For larger teams, Darktrace alerts can be forwarded to 3rd party platforms such as a SIEM, where security team decision making is augmented. Additionally, executive reports and autonomous response reduce the alert fatigue generally associated with legacy tools. Most importantly, Darktrace’s unique understanding of normal allows security teams to detect zero-days and signatureless attacks regardless of the size of the organization and how alerts are consumed.
Key Benefits of Darktrace/OT
- Anomaly-based detection and real-time response
- Secures IT, OT, and IoT in unison
- Active and Passive Asset Identification
- Automated security reporting
- Attack surface management and vulnerability assessment
- Covers all levels of the Purdue Model
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References
