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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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April 2, 2026

How Chinese-Nexus Cyber Operations Have Evolved – And What It Means For Cyber Risk and Resilience 

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Cybersecurity has traditionally organized risk around incidents, breaches, campaigns, and threat groups. Those elements still matter—but if we fixate on individual incidents, we risk missing the shaping of the entire ecosystem. Nation‑state–aligned operators are increasingly using cyber operations to establish long-term strategic leverage, not just to execute isolated attacks or short‑term objectives.  

Our latest research, Crimson Echo, shifts the lens accordingly. Instead of dissecting campaigns, malware families, or actor labels as discrete events, the threat research team analyzed Chinese‑nexus activity as a continuum of behaviors over time. That broader view reveals how these operators position themselves within environments: quietly, patiently, and persistently—often preparing the ground long before any recognizable “incident” occurs.  

How Chinese-nexus cyber threats have changed over time

Chinese-nexus cyber activity has evolved in four phases over the past two decades. This ranges from early, high-volume operations in the 1990s and early 2000s to more structured, strategically-aligned activity in the 2010s, and now toward highly adaptive, identity-centric intrusions.  

Today’s phase is defined by scale, operational restraint, and persistence. Attackers are establishing access, evaluating its strategic value, and maintaining it over time. This reflects a broader shift: cyber operations are increasingly integrated into long-term economic and geopolitical strategies. Access to digital environments, specifically those tied to critical national infrastructure, supply chains, and advanced technology, has become a form of strategic leverage for the long-term.  

How Darktrace analysts took a behavioral approach to a complex problem

One of the challenges in analyzing nation-state cyber activity is attribution. Traditional approaches often rely on tracking specific threat groups, malware families, or infrastructure. But these change constantly, and in the case of Chinese-nexus operations, they often overlap.

Crimson Echo is the result of a retrospective analysis of three years of anomalous activity observed across the Darktrace fleet between July 2022 and September 2025. Using behavioral detection, threat hunting, open-source intelligence, and a structured attribution framework (the Darktrace Cybersecurity Attribution Framework), the team identified dozens of medium- to high-confidence cases and analyzed them for recurring operational patterns.  

This long-horizon, behavior-centric approach allows Darktrace to identify consistent patterns in how intrusions unfold, reinforcing that behavioral patterns that matter.  

What the data shows

Several clear trends emerged from the analysis:

  • Targeting is concentrated in strategically important sectors. Across the dataset, 88% of intrusions occurred in organizations classified as critical infrastructure, including transportation, critical manufacturing, telecommunications, government, healthcare, and Information Technology (IT) services.  
  • Strategically important Western economies are a primary focus. The US alone accounted for 22.5% of observed cases, and when combined with major European economies including Germany, Italy, Spain and the UK, over half of all intrusions (55%) were concentrated in these regions.  
  • Nearly 63% of intrusions of intrusions began with the exploitation of internet-facing systems, reinforcing the continued risk posed by externally exposed infrastructure.  

Two models of cyber operations

Across the dataset, Chinese-nexus activity followed two operational models.  

The first is best described as “smash and grab.” These are short-horizon intrusions optimized for speed. Attackers move quickly – often exfiltrating data within 48 hours – and prioritize scale over stealth. The median duration of these compromises is around 10 days. It’s clear they are willing to risk detection for short-term gain.  

The second is “low and slow.” These operations were less prevalent in the dataset, but potentially more consequential. Here, attackers prioritize persistence, establishing durable access through identity systems and legitimate administrative tools, so they can maintain access undetected for months or even years. In one notable case, the actor had fully compromised the environment and established persistence, only to resurface in the environment more than 600 days after. The operational pause underscores both the depth of the intrusion and the actor’s long‑term strategic intent. This suggests that cyber access is a strategic asset to preserve and leverage over time, and we observed these attacks most often inin sectors of the high strategic importance.  

It’s important to note that the same operational ecosystem can employ both models concurrently, selecting the appropriate model based on target value, urgency, intended access. The observation of a “smash and grab” model should not be solely interpreted as a failure of tradecraft, but instead an operational choice likely aligned with objectives. Where “low and slow” operations are optimized for patience, smash and grab is optimized for speed; both seemingly are deliberate operational choices, not necessarily indicators of capability.  

Rethinking cyber risk

For many organizations, cyber risk is still framed as a series of discrete events. Something happens, it is detected and contained, and the organization moves on. But persistent access, particularly in deeply interconnected environments that span cloud, identity-based SaaS and agentic systems, and complex supply chain networks, creates a major ongoing exposure risk. Even in the absence of disruption or data theft, that access can provide insight into operations, dependencies, and strategic decision-making. Cyber risk increasingly resembles long-term competitive intelligence.  

This has impact beyond the Security Operations Center. Organizations need to shift how they think about governance, visibility, and resilience, and treat cyber exposure as a structural business risk instead of an incident response challenge.  

What comes next

The goal of this research is to provide a clearer understanding of how these operations work, so defenders can recognize them earlier and respond more effectively. That includes shifting from tracking indicators to understanding behaviors, treating identity providers as critical infrastructure risks, expanding supplier oversight, investing in rapid containment capabilities, and more.  

Learn more about the findings of Darktrace’s latest research, Crimson Echo: Understanding Chinese-nexus Cyber Operations Through Behavioral Analysis, by downloading the full report and summaries for business leaders, CISOs, and SOC analysts here.  

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Nathaniel Jones
VP, Security & AI Strategy, Field CISO

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April 1, 2026

AI-powered security for a rapidly growing grocery enterprise

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Protecting a complex, fast-growing retail organization

For this multi-banner grocery holding organization, cybersecurity is considered an essential business enabler, protecting operations, growth, and customer trust. The organization’s lean IT team manages a highly distributed environment spanning corporate offices, 100+ stores, distribution centers and  thousands of endpoints, users, and third-party connections.

Mergers and acquisitions fueled rapid growth, but they also introduced escalating complexity that constrained visibility into users, endpoints, and security risks inherited across acquired environments.

Closing critical visibility gaps with limited resources

Enterprise-wide visibility is a top priority for the organization, says the  Vice President of Information Technology. “We needed insights beyond the perimeter into how users and devices were behaving across the organization.”

A security breach that occurred before the current IT leadership joined the company reinforced the urgency and elevated cybersecurity to an executive-level priority with a focus on protecting customer trust. The goal was to build a multi-layered security model that could deliver autonomous, enterprise-wide protection without adding headcount.

Managing cyber risk in M&A

Mergers and acquisitions are central to the grocery holding company’s growth strategy. But each transaction introduces new cyber risk, including inherited network architectures, inconsistent tooling, excessive privileges, and remnants of prior security incidents that were never fully remediated.

“Our M&A targets range from small chains with a single IT person and limited cyber tools to large chains with more developed IT teams, toolsets and instrumentation,” explains the VP of IT. “We needed a fast, repeatable, and reliable way to assess cyber risk before transactions closed.”

AI-driven security built for scale, speed, and resilience

Rather than layering additional point tools onto an already complex environment, the retailer adopted the Darktrace ActiveAI Security Platform™ in 2020 as part of a broader modernization effort to improve resilience, close visibility gaps, and establish a security foundation that could scale with growth.

“Darktrace’s AI-driven approach provided the ideal solution to these challenges,” shares the VP of IT. “It has empowered our organization to maintain a robust security strategy, ensuring the protection of our network and the smooth operation of our business.”

Enterprise-wide visibility into traffic  

By monitoring both north-south and east-west traffic and applying Self-Learning AI, Darktrace develops a dynamic understanding of how users and devices normally behave across locations, roles, and systems.

“Modeling normal behavior across the environment enables us to quickly spot behavior that doesn’t fit. Even subtle changes that could signal a threat but appear legitimate at first glance,” explains the VP of IT.

Real-time threat containment, 24/7

Adopting autonomous response has created operational breathing room for the security team, says the company’s Cybersecurity  Engineer.

“Early on, we enabled full Darktrace autonomous mode and we continue to do so today,” shares the IT Security Architect. “Allowing the technology to act first gives us the time we need to investigate incidents during business hours without putting the business at risk.”

Unified, actionable view of security ecosystem

The grocery retailer integrated Darktrace with its existing security ecosystem of firewalls, vulnerability management tools, and endpoint detection and response, and the VP of IT described the adoption process as “exceptionally smooth.”

The team can correlate enterprise-wide security data for a unified and actionable picture of all activity and risk. Using this “single pane of glass” approach, the retailer trains Level 1 and Level 2 operations staff to assist with investigations and user follow-ups, effectively extending the reach of the security function without expanding headcount.

From reactive defense to security at scale

With Darktrace delivering continuous visibility, autonomous containment, and integrated security workflows, the organization has strengthened its cybersecurity posture while improving operational efficiency. The result is a security model that not only reduces risk, but also supports growth, resilience, and informed decision-making at the business level.

Faster detection, faster resolution

With autonomous detection and response, the retailer can immediately contain risk while analysts investigate and validate activity. With this approach, the company can maintain continuous protection even outside business hours and reduce the chance of lateral spread across systems or locations.

Enterprise-grade protection with a lean team

From cloud environments to clients to SaaS collaboration tools, Darktrace provides holistic autonomous AI defense, processing petabytes of the organization’s network traffic and investigating millions of individual events that could be indicative of a wider incident.

Today, Darktrace autonomously conducts the majority of all investigations on behalf of the IT team, escalating only a tiny fraction for analyst review. The impact has been profound, freeing analysts from endless alerts and hours of triage so they can focus on more valuable, proactive, and gratifying work.

“From an operational perspective, Darktrace gives us time back,” says the Cybersecurity Engineer. More importantly, says the VP of IT, “it gives us peace of mind that we’re protected even if we’re not actively monitoring every alert.”

A strategic input for M&A decision-making

One of the most strategic outcomes has been the role of cybersecurity on M&A. 90 days prior to closing a transaction, the security team uses Darktrace alongside other tools to perform a cyber risk assessment of the potential acquisition. “Our approach with Darktrace has consistently identified gaps and exposed risks,” says the VP of IT, including:

  • Remnants of previous incidents that were never fully remediated
  • Network configurations with direct internet exposure
  • Excessive administrative privileges in Active Directory or on critical hosts

While security findings may not alter deal timelines, the VP of IT says they can have enormous business implications. “With early visibility into these risks, we can reduce exposure to inherited cyber threats, strengthen our position during negotiations, and establish clear remediation requirements.”

A security strategy built to evolve with the business

As the holding group expands its cloud footprint, it will extend Darktrace protections into Azure, applying the same AI-driven visibility and autonomous response to cloud workloads. The VP of IT says Darktrace's evolving capabilities will be instrumental in addressing the organization’s future cybersecurity needs and ability to adapt to the dynamic nature of cloud security.

“With Darktrace’s AI-driven approach, we have moved beyond reactive defense, establishing a resilient security foundation for confident expansion and modernization.”

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