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October 20, 2025

Salt Typhoon侵入事例に対するダークトレースの視点

中国に関係のあるサイバー諜報グループ、Salt TyphoonがDLLサイドローディングやゼロデイエクスプロイト等のステルス手法を使って世界的なインフラを狙っていることが確認されました。ダークトレースは最近Salt Typhoonの戦術と一致する初期の侵入アクティビティを検知しました。これは国家が支援する執拗な脅威に対する防御において従来のシグネチャベースの手法ではなく異常ベースの検知が重要であることを裏付けています。
Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Nathaniel Jones
VP, Security & AI Strategy, Field CISO
Written by
Sam Lister
Specialist Security Researcher
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20
Oct 2025

Salt Typhoonとは?

Salt Typhoonは、現在世界のインフラを狙っている最も執拗かつ巧妙なサイバー脅威の1つです。国家が支援する中国のアクターとされるこのAPT(Advanced Persistent Threat)グループは、主に米国の通信プロバイダー、エネルギーネットワーク、政府システムを標的とした、ー連のインパクトの大きいキャンペーンを実行しています。

少なくとも2019年から活動しており、Earth Estries、GhostEmperor、UNC2286としても記録されているこのグループは、エッジデバイスのエクスプロイトに高度な能力を示し、深い永続性を維持しつつ80か国以上において機密性の高いデータの抜き出しを行っています。公になっている被害の報告はほとんど米国の標的に集中していますが、Salt TyphoonのオペレーションはEMEA(ヨーロッパ、中東、アフリカ)地域にも拡大し、通信、政府機関、テクノロジー企業等が標的とされています。カスタムマルウェアの使用、およびインパクトの大きい脆弱性のエクスプロイト(例: Ivanti、Fortinet、Cisco等)は、インテリジェンス収集と地政学的影響を組み合わせたこのグループの戦略的性質を表しています [1]。

ゼロデイエクスプロイト、難読化テクニック、水平移動戦術を駆使することにより、Salt Typhoonは検知を回避し機密性の高い環境に長期間のアクセスを維持することのできる、恐るべき能力を実証しています。このグループのオペレーションにより合法的傍受システムが露出し、数百万のユーザーのメタデータが漏洩、必要不可欠なサービスの中断を招き、世界中で情報機関と民間パートナーの協調した対応が促されました。組織が自社の脅威モデルを評価するなかで、Salt Typhoonは国家が支援するサイバーオペレーションの進化と、積極的な防御戦略が緊急に必要であることをはっきりと思い出させる存在です。

Darktraceのカバレッジ

Darktraceはヨーロッパの通信企業において、DLLサイドローディングと正規のソフトウェアの悪用によるステルス性維持と実行を含む、Salt Typhoonのものとして知られているTTP(戦術、技法、手順)を確認しました。

初期アクセス

侵入は2025年7月、CVE-2025-5777のエクスプロイトから始まりました。これはCitrix NetScaler Gatewayアプライアンスに影響する脆弱性です。脅威アクターはここから、クライアントのMCS(Machine Creation Services)サービス内の Citrix VDA(Virtual Delivery Agent)ホストに移動しました。この侵入の初期のアクセス活動はSoftEther VPNサービスと関連するとみられるエンドポイントから発生しており、最初からインフラ難読化が行われていたことがわかります。

ツール

Darktraceはその後、この脅威アクターが複数のCitrix VDAホストに対し、高い確率でSNAPPYBEE(Deed RATとしても知られる) [2][3] であるとみられるバックドアを設置したことを検知しました。このバックドアはこれらの内部エンドポイントに対して、Norton Antivirus、Bkav Antivirus、IObit Malware Fighterなどのアンチウイルスソフトウェアの正規の実行形式ファイルと共にDLLとして仕掛けられました。このアクティビティのパターンは、攻撃者が正規のアンチウイルスソフトウェアを使ったDLLサイドローディングによりペイロードを実行しようとしたことを示しています。Salt Typhoonおよび類似のグループは過去にもこのテクニックを使用してきており[4][5]、これにより信頼されるソフトウェアの陰でペイロードを実行し従来型のセキュリティコントロールを回避することを可能にしています。

コマンド&コントロール(C2)

この脅威アクターが設置したバックドアはLightNode VPSエンドポイントをC2に使用し、HTTPと不明なTCPベースのプロトコルの両方を使って通信していました。このように二重のチャネルを使っていることは、Salt Typhoonが非標準プロトコルを多層的に使用して検知を回避することで知られていることと一致しています。バックドアに表示されたHTTP通信には、Internet Explorerの User-Agentヘッダーを持つPOSTリクエストや“/17ABE7F017ABE7F0” のようなTarget URIパターンが含まれていました。侵害されたエンドポイントが接続したC2ホストの1つはaar.gandhibludtric[.]com (38.54.63[.]75)であり、最近Salt Typhoonとの関連が確認されたドメインです[6]。

検知のタイムライン

Darktraceは侵入の初期段階に対して高確度の検知結果を生成しました。初期のツール使用とC2アクティビティは、Darktrace Cyber AI AnalystTMによる調査と、Darktraceのモデルの両方によって明確にカバーされていました。脅威アクターが高度であったにもかかわらず、侵入アクティビティはこれらの攻撃の初期段階から先へ進展する前に識別され、修正されました。Darktraceのタイムリーかつ高確度の検知が脅威の無害化に重要な役割を果たしたものと思われます。

Cyber AI Analystの知見

Darktrace Cyber AI Analyst は侵入の初期段階においてDarktraceが検知したモデルアラートを自律的に調査しました。この調査を通じ、Cyber AI Analystは初期のツール使用とC2イベントを突き止め、これらをつなぎ合わせて攻撃の進行を表す1つのインシデントにまとめました。

Cyber AI Analyst weaved together separate events from the intrusion into broader incidents summarizing the attacker’s progression.
図1: Cyber AI Analystは侵入アクティビティからの個別のイベントをつなぎ合わせて全体のインシデントを作成し、攻撃の進行状況を示しました。

まとめ

TTPやステージングパターン、インフラ、マルウェアの共通点に基づき、ダークトレースは一定の確信を持って観察されたアクティビティがSalt Typhoon/Earth Estries (ALA GhostEmperor/UNC2286)と一致していると評価しました。Salt Typhoonは引き続きそのステルス性、永続性、正規ツールの悪用によって防御者を悩ませています。攻撃者が通常のオペレーションに紛れ込もうとする傾向が高まるなかで、かすかな逸脱を識別し分散したシグナルを相関付けるには、動作の異常を検知することが不可欠となります。Salt Typhoonの特徴である変化する手法、そして信頼されるソフトウェアやインフラを別の目的に使用する能力により、従来の手法だけでは今後も検知が難しいことが確実です。この侵入インシデントは積極的な防御の重要性を示しており、そこではシグネチャの照合だけにとどまらない異常ベースの検知が、初期段階のアクティビティを明らかにする上で決定的な役割を果たします。

本稿の執筆には Nathaniel Jones (VP, Security & AI Strategy, FCISO)、Sam Lister(Specialist Security Researcher)、Emma Foulger(Global Threat Research Operations Lead)、Adam Potter(Senior Cyber Analystが協力しました。

編集:Ryan Traill(Analyst Content Lead)

付録

侵害インジケータ(IoC)

IoC-タイプ-説明 + 確度

89.31.121[.]101 – IP Address – Possible C2 server

hxxp://89.31.121[.]101:443/WINMM.dll - URI – Likely SNAPPYBEE download

b5367820cd32640a2d5e4c3a3c1ceedbbb715be2 - SHA1 – Likely SNAPPYBEE download

hxxp://89.31.121[.]101:443/NortonLog.txt - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/123.txt - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/123.tar - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/pdc.exe - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443//Dialog.dat - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/fltLib.dll - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/DisplayDialog.exe - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/DgApi.dll - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/dbindex.dat - URI - Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/1.txt - URI - Possible DLL side-loading activity

hxxp://89.31.121[.]101:443/imfsbDll.dll – Likely DLL side-loading activity

hxxp://89.31.121[.]101:443/imfsbSvc.exe - URI – Likely DLL side-loading activity

aar.gandhibludtric[.]com – Hostname – Likely C2 server

38.54.63[.]75 – IP – Likely C2 server

156.244.28[.]153 – IP – Possible C2 server

hxxp://156.244.28[.]153/17ABE7F017ABE7F0 - URI – Possible C2 activity

MITRE TTP

テクニック | 説明

T1190 | Exploit Public-Facing Application - Citrix NetScaler Gateway compromise

T1105 | Ingress Tool Transfer – Delivery of backdoor to internal hosts

T1665 | Hide Infrastructure – Use of SoftEther VPN for C2

T1574.001 | Hijack Execution Flow: DLL – Execution of backdoor through DLL side-loading

T1095 | Non-Application Layer Protocol – Unidentified application-layer protocol for C2 traffic

T1071.001| Web Protocols – HTTP-based C2 traffic

T1571| Non-Standard Port – Port 443 for unencrypted HTTP traffic

侵入時のDarktraceモデルアラート

Anomalous File::Internal::Script from Rare Internal Location

Anomalous File::EXE from Rare External Location

Anomalous File::Multiple EXE from Rare External Locations

Anomalous Connection::Possible Callback URL

Antigena::Network::External Threat::Antigena Suspicious File Block

Antigena::Network::Significant Anomaly::Antigena Significant Server Anomaly Block

Antigena::Network::Significant Anomaly::Antigena Controlled and Model Alert

Antigena::Network::Significant Anomaly::Antigena Alerts Over Time Block

Antigena::Network::External Threat::Antigena File then New Outbound Block  

参考文献

[1] https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-239a

[2] https://www.trendmicro.com/en_gb/research/24/k/earth-estries.html

[3] https://www.trendmicro.com/content/dam/trendmicro/global/en/research/24/k/earth-estries/IOC_list-EarthEstries.txt

[4] https://www.trendmicro.com/en_gb/research/24/k/breaking-down-earth-estries-persistent-ttps-in-prolonged-cyber-o.html

[5] https://lab52.io/blog/deedrat-backdoor-enhanced-by-chinese-apts-with-advanced-capabilities/

[6] https://www.silentpush.com/blog/salt-typhoon-2025/

このブログで提供されるコンテンツはダークトレースが一般的な情報提供の目的でのみ公開するものであり、サイバーセキュリティに関するトピック、傾向、インシデント、出来事についての、公開の時点における当社の理解を反映したものです。当社は内容の正確性と重要性の担保に努めていますが、情報は明示的暗黙的を問わず、何らの表明あるいは保証も伴わわない「そのまま」の状態で提供されるものです。ダークトレースは本書に含まれる情報の完全性、正確性、信頼性、適時性について何らの責任も負わず、すべての保証を明示的に否認します。

本ブログに含まれるいかなる内容も法的、技術的、技術的助言を構成するものではなく、読者は本書に含まれる情報に基づいて行動する前に資格を持った専門家に相談されることをお勧めします。第三者の組織、技術、脅威アクター、インシデントに対する言及は情報目的のみであり、提携、承認、推奨を暗に意味するものではありません。

ダークトレース、その関連会社、従業員、あるいは代理人は、本ブログの情報の使用またはこれに対する信頼により生じた、いかなる損失、損害、危害についても責任を負いません。

サイバーセキュリティを取り巻く環境は急激に変化しており、ブログの内容は古くなるあるいは新しいものに代替される可能性があります。当社は任意のコンテンツを更新、変更、あるいは削除する権利を留保します。

Inside the SOC
Darktrace cyber analysts are world-class experts in threat intelligence, threat hunting and incident response, and provide 24/7 SOC support to thousands of Darktrace customers around the globe. Inside the SOC is exclusively authored by these experts, providing analysis of cyber incidents and threat trends, based on real-world experience in the field.
Written by
Nathaniel Jones
VP, Security & AI Strategy, Field CISO
Written by
Sam Lister
Specialist Security Researcher

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May 20, 2026

Prompt Security in Enterprise AI: Strengths, Weaknesses, and Common Approaches

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How enterprise AI Agents are changing the risk landscape  

Generative AI Agents are changing the way work gets done inside enterprises, and subsequently how security risks may emerge. Organizations have quickly realized that providing these agents with wider access to tooling, internal information, and granting permissions for the agent to perform autonomous actions can greatly increase the efficiency of employee workflows.

Early deployments of Generative AI systems led many organizations to scope individual components as self-contained applications: a chat interface, a model, and a prompt, with guardrails placed at the boundary. Research from Gartner has shown that while the volume and scope of Agentic AI deployments in enterprise environments is rapidly accelerating, many of the mechanisms required to manage risk, trust, and cost are still maturing.

The issue now resides on whether an agent can be influenced, misdirected, or manipulated in ways that leads to unsafe behavior across a broader system.

Why prompt security matters in enterprise AI

Prompt security matters in enterprise AI because prompts are the primary way users and systems interact with Agentic AI models, making them one of the earliest and most visible indicators of how these systems are being used and where risk may emerge.

For security teams, prompt monitoring is a logical starting point for understanding enterprise AI usage, providing insight into what types of questions are being asked and tasks are being given to AI Agents, how these systems are being guided, and whether interactions align with expected behavior. Complete prompt security takes this one step further, filtering out or blocking sensitive or dangerous content to prevent risks like prompt injection and data leakage.

However, visibility only at the prompt layer can create a false sense of security. Prompts show what was asked, but not always why it was asked, or what downstream actions were triggered by the agent across connected systems, data sources, or applications.

What prompt security reveals  

The primary function of prompt security is to minimize risks associated with generative and agentic AI use, but monitoring and analysis of prompts can also grant insight into use cases for particular agents and model. With comprehensive prompt security, security teams should be able to answer the following questions for each prompt:

  • What task was the user attempting to complete?
  • What data was included in the request, and was any of the data high-risk or confidential?
  • Was the interaction high-risk, potentially malicious, or in violation of company policy?
  • Was the prompt anomalous (in comparison to previous prompts sent to the agent / model)?

Improving visibility at this layer is a necessary first step, allowing organizations to establish a baseline for how AI systems are being used and where potential risks may exist.  

Prompt security alone does not provide a complete view of risk. Further data is needed to understand how the prompt is interpreted, how context is applied, what autonomous actions the agent takes (if any), or what downstream systems are affected. Understanding the outcome of a query is just as important for complete prompt security as understanding the input prompt itself – for example, a perfectly normal, low-risk prompt may inadvertently result in an agent taking a high-risk action.

Comprehensive AI security systems like Darktrace / SECURE AI can monitor and analyze both the prompt submitted to a Generative AI system, as well as the responses and chain-of-thought of the system, providing greater insight into the behavior of the system. Darktrace / SECURE AI builds on the core Darktrace methodology, learning the expected behaviors of your organization and identifying deviations from the expected pattern of life.

How organizations address prompt security today

As prompt-level visibility has become a focus, a range of approaches have emerged to make this activity more observable and controllable. Various monitoring and logging tools aim to capture prompt inputs to be analyzed after the fact.  

Input validation and filtering systems attempt to intervene earlier, inspecting prompts before they reach the model. These controls look for known jailbreak patterns, language indicative of adversarial attacks, or ambiguous instructions which could push the system off course.

Importantly, for a prompt security solution to be accurate and effective, prompts must be continually observed and governed, rather than treated as a point-in-time snapshot.  

Where prompt security breaks down in real environments

In more complex environments, especially those involving multiple agents or extensive tool use, AI security becomes harder to define and control.

Agent-to-Agent communications can be harder to monitor and trace as these happen without direct user interaction. Communication between agents can create routes for potential context leakage between agents, unintentional privilege escalation, or even data leakage from a higher privileged agent to a lower privileged one.

Risk is shaped not just by what is asked, but by the conditions in which that prompt operates and the actions an agent takes. Controls at the orchestration layer are starting to reflect this reality. Techniques such as context isolation, scoped memory, and role-based boundaries aim to limit how far a prompt’s influence can extend.  

Furthermore, Shadow AI usage can be difficult to monitor. AI systems that are deployed outside of formal governance structures and Generative AI systems hosted on unknown endpoints can fly under the radar and can go unseen by monitoring tools, leaving a critical opening where adversarial prompts may go undetected. Darktrace / SECURE AI features comprehensive detection of Shadow AI usage, helping organizations identify potential risk areas.

How prompt security fits in a broader AI risk model

Prompt security is an important starting point, but it is not a complete security strategy. As AI systems become more integrated into enterprise environments, the risks extend to what resources the system can access, how it interprets context, and what actions it is allowed to take across connected tools and workflows.

This creates a gap between visibility and control. Prompt security alone allows security teams to observe prompt activity but falls short of creating a clear understanding of how that activity translates into real-world impact across the organization.

Closing that gap requires a broader approach, one that connects signals across human and AI agent identities, SaaS, cloud, and endpoint environments. It means understanding not just how an AI system is being used, but how that usage interacts with the rest of the digital estate.

Prompt security, in that sense, is less of a standalone solution and more of an entry point into a larger problem: securing AI across the enterprise as a whole.

Explore how Darktrace / SECURE AI brings prompt security to enterprises

Darktrace brings more than a decade of AI expertise, built on an enterprise‑wide platform designed to operate in and understand the behaviors of the complex, ambiguous environments where today’s AI now lives. With Darktrace / SECURE AI, enterprises can safely adopt, manage, monitor, and build AI within their business.  

Learn about Darktrace / SECURE AI here.

Sign up today to stay informed about innovations across securing AI.

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May 20, 2026

State of AI Cybersecurity 2026: 77% of security stacks include AI, but trust is lagging

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Findings in this blog are taken from Darktrace’s annual State of AI Cybersecurity Report 2026.

AI is a contributing member of nearly every modern cybersecurity team. As we discussed earlier in this blog series, rapid AI adoption is expanding the attack surface in ways that security professionals have never before experienced while also empowering attackers to operate at unprecedented speed and scale. It’s only logical that defenders are harnessing the power of AI to fight back.

After all, AI can help cybersecurity teams spot the subtle signs of novel threats before humans can, investigate events more quickly and thoroughly, and automate response. But although AI has been widely adopted, this technology is also frequently misunderstood, and occasionally viewed with suspicion.

For CISOs, the cybersecurity marketplace can be noisy. Making sense of competing vendors’ claims to distinguish the solutions that truly deliver on AI’s full potential from those that do not isn’t always easy. Without a nuanced understanding of the different types of AI used across the cybersecurity stack, it is difficult to make informed decisions about which vendors to work with or how to gain the most value from their solutions. Many security leaders are turning to Managed Security Service Providers (MSSPs) for guidance and support.

The right kinds of AI in the right places?

Back in 2024, when we first conducted this annual survey, more than a quarter of respondents were only vaguely familiar with generative AI or hadn’t heard of it at all. Today, GenAI plays a role in 77% of security stacks. This percentage marks a rapid increase in both awareness and adoption over a relatively short period of time.

According to security professionals, different types of AI are widely integrated into cybersecurity tooling:

  • 67% report that their organization’s security stack uses supervised machine learning
  • 67% report that theirs uses agentic AI
  • 58% report that theirs uses natural language processing (NLP)
  • 35% report that theirs uses unsupervised machine learning

But their responses suggest that organizations aren’t always using the most valuable types of AI for the most relevant use cases.

Despite all the recent attention AI has gotten, supervised machine learning isn’t new. Cybersecurity vendors have been experimenting with models trained on hand-labeled datasets for over a decade. These systems are fed large numbers of examples of malicious activity – for instance, strains of ransomware – and use these examples to generalize common indicators of maliciousness – such as the TTPs of multiple known ransomware strains – so that the models can identify similar attacks in the future. This approach is more effective than signature-based detection, since it isn’t tied to an individual byte sequence or file hash. However, supervised machine learning models can miss patterns or features outside the training data set. When adversarial behavior shifts, these systems can’t easily pivot.

Unsupervised machine learning, by contrast, can identify key patterns and trends in unlabeled data without human input. This enables it to classify information independently and detect anomalies without needing to be taught about past threats. Unsupervised learning can continuously learn about an environment and adapt in real time.

One key distinction between supervised and unsupervised machine learning is that supervised learning algorithms require periodic updating and re-training, whereas unsupervised machine learning trains itself while it works.

The question of trust

Even as AI moves into the mainstream, security professionals are eyeing it with a mix of enthusiasm and caution. Although 89% say they have good visibility into the reasoning behind AI-generated outputs, 74% are limiting AI’s ability to take autonomous action in their SOC until explainability improves. 86% do not allow AI to take even small remediation actions without human oversight.

This model, commonly known as “human in the loop,” is currently the norm across the industry. It seems like a best-of-both-worlds approach that allows teams to experience the benefits of AI-accelerated response without relinquishing control – or needing to trust an AI system.

Keeping humans somewhat in the loop is essential for getting the best out of AI. Analysts will always need to review alerts, make judgement calls, and set guardrails for AI's behavior. Their input helps AI models better understand what “normal” looks like, improving their accuracy over time.

However, relying on human confirmation has real costs – it delays response, increases the cognitive burden analysts must bear, and creates potential coverage gaps when security teams are overwhelmed or unavailable. The traditional model, in which humans monitor and act on every alert, is no longer workable at scale.

If organizations depend too heavily on in-the-loop humans, they risk recreating the very problem AI is meant to solve: backlogs of alerts waiting for analyst review. Removing the human from the loop can buy back valuable time, which analysts can then invest in building a proactive security posture. They can also focus more closely on the most critical incidents, where human attention is truly needed.

Allowing AI to operate autonomously requires trust in its decision-making. This trust can be built gradually over time, with autonomous operations expanding as trust grows. But it also requires knowledge and understanding of AI — what it is, how it works, and how best to deploy it at enterprise scale.

Looking for help in all the right places

To gain access to these capabilities in a way that’s efficient and scalable, growing numbers of security leaders are looking for outsourced support. In fact, 85% of security professionals prefer to obtain new SOC capabilities in the form of a managed service.

This makes sense: Managed Security Service Providers (MSSPs) can deliver deep, continuously available expertise without the cost and complexity of building an in-house team. Outsourcing also allows organizations to scale security coverage up or down as needs change, stay current with evolving threats and regulatory requirements, and leverage AI-native detection and response without needing to manage the AI tools themselves.

Preferences for MSSP-delivered security operations are particularly strong in the education, energy (87%), and healthcare sectors. This makes sense: all are high-value targets for threat actors, and all tend to have limited cybersecurity budgets, so the need for a partner who can deliver affordable access to expertise at scale is strong. Retailers also voiced a strong preference for MSSP-delivered services. These companies are tasked with managing large volumes of consumer personal and financial data, and with transforming an industry traditionally thought of as a late adopter to a vanguard of cyber defense. Technology companies, too, have a marked preference for SOC capabilities delivered by MSSPs. This may simply be because they understand the complexity of the threat landscape – and the advantages of specialized expertise — so well.

In order to help as many organizations as possible – from major enterprises to small and midmarket companies – benefit from enterprise-grade, AI-native security, Darktrace is making it easier for MSSPs to deliver its technology. The ActiveAI Security Portal introduces an alert dashboard designed to increase the speed and efficiency of alert triage, while a new AI-powered managed email security solution is giving MSSPs an edge in the never-ending fight against advanced phishing attacks – helping partners as well as organizations succeed on the frontlines of cyber defense.

Explore the full State of AI Cybersecurity 2026 report for deeper insights into how security leaders are responding to AI-driven risks.

Learn more about securing AI in your enterprise.

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