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July 2, 2025

CVE公開前の脅威検知脆弱性が公開される前に悪意あるアクティビティを識別した10件の事例

DarktraceはAI駆動の異常検知を利用してCVEが公開される前にサイバー脅威を識別することができます。動作のパターンを分析することにより、Darktraceは組織がゼロデイエクスプロイトを初期段階で検知し封じ込めるのに役立ちます。このプロアクティブなアプローチにより、国家レベルの脅威アクター、ランサムウェアギャング、そして脅威ランドスケープ全体にわたり進化し続ける脅威に対してサイバーセキュリティ体制を強化することができます。
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
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02
Jul 2025

CVEの追跡だけでは不十分:コンテキストがきわめて重要である理由

脆弱性とは、攻撃者が不正にアクセスを取得したり、正常なオペレーションを妨害したりするために悪用することのできる、システム内のウィークポイントです。CVE(Common  Vulnerabilities and  Exposures)とは、公開されているサイバーセキュリティ脆弱性のリストであり、サイバーセキュリティコミュニティはこれを追跡してリスクを緩和します。

脆弱性が発見されると、標準的な手順としてはこれをベンダーまたは対応する組織に報告することにより、彼らはパッチまたは修正を作成して配布し、その後詳細を公開するというものです。これは、責任ある開示と呼ばれている方法です。

2024年には記録を塗り替える40,000件のCVEが報告され、Forum for Incident Response and  Security Teams (FIRST) によれば2025年にはそれを上回る件数が予測されている[1]  なかで、異常検知はこれらの潜在的リスクを識別するために不可欠です。ゼロデイのエクスプロイトと脆弱性の公開の間のギャップはかなり大きい場合もあり、ネットワーク上でエクスプロイトが行われていないかを遡及的に見つけ出そうとすることは、特にシグネチャベースのアプローチをとっている場合非常に困難です。

CVE公開に頼ることなく脅威を検知

普段とは異なるログインのパターンやデータ転送など、ネットワークやシステム内で発生した異常な動作は、サイバー攻撃が試みられている、内部関係者による脅威、あるいはシステムが侵害されている兆候である場合があります。Darktraceはルールやシグネチャに依存しないため、問題のデバイスまたはアセットについての完全なコンテキストがなくても、異常から悪意あるアクティビティを検知することができます。

たとえば、昨年末のFortinetに対するエクスプロイト攻撃発生時に、Darktraceの脅威リサーチチームはさまざまなFortinet脆弱性のエクスプロイト、特にCVE  2024-23113について調査していました。その頃MandiantがCVE  2024-47575に関するセキュリティアドバイザリを発行しましたが、その内容はDarktraceの調査結果と非常によく一致していました。

Darktraceの脅威調査チームはこのような回顧的分析によりさまざまな検知結果を広範な脅威ランドスケープに照らして理解し、さらなるコンテキストを追加するために利用しています。

以下は、脆弱性が公開される何日も前、場合によっては何週間も前にDarktraceが検知した昨年の10件の事例です。

ten examples from the past year where Darktrace detected malicious activity days or even weeks before a vulnerability was publicly disclosed.

CVE公開前のエクスプロイトの傾向

多くの場合、エクスプロイトされた脆弱性の開示は、高度な脅威アクターによるゼロデイを使った侵害に対する、インシデント対応調査の結果として行われます。脆弱性が登録され、エクスプロイトされたことが公表されると、攻撃者と防御者による攻撃  vs. パッチの競争が始まります。

高いスキルと豊富なリソースを持った国家アクターは、その目的を達成するためにさまざまな能力を駆使することで知られていますが、それにはゼロデイの利用も含まれます。多くのケースで、CVE公開前のアクティビティはローアンドスロー型で数か月も継続し、オペレーションの安全性は高い傾向にあります。CVE公開後は参入障壁が下がり、よりスキルの低い、リソースをあまり持たない攻撃者、たとえばランサムウェアギャングのようなグループでもその脆弱性を悪用することができ、大きな被害が発生します。エクスプロイトされた脆弱性の公開前、公開後において、異なる2つのタイプのアクティビティがみられることが多いのはそのためです。

ダークトレースはこの一連の流れを、昨年、前述のFortinetおよびPAN  OS脅威アクターによる攻撃のいくつかにおいても確認しています。国家アクターによる脆弱性のエクスプロイトが見られた後、ランサムウェアギャングが多くの組織に被害をもたらしていました  [2]

今年の春発生した、中国の脅威アクターが関係するSAP  Netweaverエクスプロイトでも、それに続いてランサムウェアインシデントが観測されており、同じ傾向がみられます[3]

自律遮断

異常ベースの検知は、CVE公開前であっても悪意あるアクティビティを識別できるという利点があります。しかし、セキュリティチームにはすばやく封じ込めアクティビティを隔離するという仕事が残っています。

たとえば、2025年前半に起こったIvanti連鎖エクスプロイト事案において、ある顧客は自社ネットワーク上でDarktraceの自律遮断機能を有効に設定していました。その結果、Darktraceは内部の接続をブロックし、影響を受けたデバイスに対して「生活パターン」を強制することにより、疑わしい接続をシャットダウンして攻撃を封じ込めることができました。

このDarktraceによる検知および対処はCVE公開の11日前に実行されており、異常ベースのアプローチの利点を実証しています。    

一部のケースでは、Darktraceがデバイスに対する悪意あるエクスプロイトを脆弱性が公開される数日前に阻止したことが報告されています。

たとえば、ConnectWiseに対するエクスプロイト攻撃発生時、ある顧客において、リモートアクセスを介して悪意あるソフトウェアがインストールされたことをDarktraceが検知しました。さらに調査を進めると4台のサーバーが影響を受けていることが判明し、その間、自律遮断機能がアウトバウンド接続をブロックし、影響を受けたデバイスに対して生活パターンを強制しました。

シグネチャを超えて:CVE公開前に異常を見つける

動作パターンを分析し続けることにより、ユーザー、システム、ネットワークから通常と異なるアクティビティを見つけ出し、セキュリティ侵害かもしれない異常を検知することができます。

継続的な監視とこれらの動作からの学習を通じて、異常ベースのセキュリティシステムは、従来のシグネチャベースのソリューションでは見過ごされてしまうかもしれない脅威を検知することができ、同時に脅威のTTP(Tactics,  Techniques and  Procedures)についての詳細な情報を提供することができます。このようなビヘイビアインテリジェンスによりCVE公開前の検知が可能になり、より適応性の高いセキュリティ体制の構築、および変化し続ける脅威ランドスケープに応じたシステムの進化が可能になります。

Darktraceの自己学習型AIアプローチ

10年以上にわたりサイバーセキュリティAIをリードしてきたDarktraceは、適切なAIを組み合わせて最適な結果を得るための専門技術を有しています。Darktraceの自己学習型AIは多層的なAIアプローチを使用して、それぞれの組織から学習することにより、脆弱性が公開される前、多くの場合何日も、あるいは何週間も前に、悪意あるアクティビティを検知し対処することができます。

機械学習、深層学習、LLM、自然言語処理を含む多様なAIテクニックを戦略的に組み合わせ、連続的、階層的に統合することにより、Darktraceの多層的AIアプローチはそれぞれの組織専用の、変化する脅威ランドスケープに適応する強力な防御メカニズムを提供します。

ベイズ学習やビヘイビアクラスタリングといったテクニックを用いて、Darktraceはさまざまなモデルを適応的に評価し、エンティティの動作を正確に理解することが可能です。このビヘイビア分析のレイヤーにより、特定のデバイスやシステムからのまばらなデータであっても、類似のエンティティの持つパターンを検知し動作を予測することが可能になります。AIはこの基準枠を絶えず調整し続け、動的な環境での有効性を維持します。

DarktraceのAIについてさらに詳しく知るには、サイバーセキュリティに対するAIのさまざまな応用を解説した AI  Arsenal (多層的AI装備)ホワイトペーパーをご覧ください。

参考資料:

  1. https://www.first.org/blog/20250607-Vulnerability-Forecast-for-2025
  2. https://cloud.google.com/blog/topics/threat-intelligence/fortimanager-zero-day-exploitation-cve-2024-47575
  3. https://thehackernews.com/2025/05/china-linked-hackers-exploit-sap-and.html

関連するDarktraceのブログ:

*顧客による報告後確認されたもの

**2024年1月に更新されたブログは最新データを反映

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

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October 20, 2025

Salty Much: Darktrace’s view on a recent Salt Typhoon intrusion

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What is Salt Typhoon?

Salt Typhoon represents one of the most persistent and sophisticated cyber threats targeting global critical infrastructure today. Believed to be linked to state-sponsored actors from the People’s Republic of China (PRC), this advanced persistent threat (APT) group has executed a series of high-impact campaigns against telecommunications providers, energy networks, and government systems—most notably across the United States.

Active since at least 2019, the group—also tracked as Earth Estries, GhostEmperor, and UNC2286—has demonstrated advanced capabilities in exploiting edge devices, maintaining deep persistence, and exfiltrating sensitive data across more than 80 countries. While much of the public reporting has focused on U.S. targets, Salt Typhoon’s operations have extended into Europe, the Middle East, and Africa (EMEA) where it has targeted telecoms, government entities, and technology firms. Its use of custom malware and exploitation of high-impact vulnerabilities (e.g., Ivanti, Fortinet, Cisco) underscores the strategic nature of its campaigns, which blend intelligence collection with geopolitical influence [1].

Leveraging zero-day exploits, obfuscation techniques, and lateral movement strategies, Salt Typhoon has demonstrated an alarming ability to evade detection and maintain long-term access to sensitive environments. The group’s operations have exposed lawful intercept systems, compromised metadata for millions of users, and disrupted essential services, prompting coordinated responses from intelligence agencies and private-sector partners worldwide. As organizations reassess their threat models, Salt Typhoon serves as a stark reminder of the evolving nature of nation-state cyber operations and the urgent need for proactive defense strategies.

Darktrace’s coverage

In this case, Darktrace observed activity in a European telecommunications organisation consistent with Salt Typhoon’s known tactics, techniques and procedures (TTPs), including dynamic-link library (DLL) sideloading and abuse of legitimate software for stealth and execution.

Initial access

The intrusion likely began with exploitation of a Citrix NetScaler Gateway appliance in the first week of July 2025. From there, the actor pivoted to Citrix Virtual Delivery Agent (VDA) hosts in the client’s Machine Creation Services (MCS) subnet. Initial access activities in the intrusion originated from an endpoint potentially associated with the SoftEther VPN service, suggesting infrastructure obfuscation from the outset.

Tooling

Darktrace subsequently observed the threat actor delivering a backdoor assessed with high confidence to be SNAPPYBEE (also known as Deed RAT) [2][3] to multiple Citrix VDA hosts. The backdoor was delivered to these internal endpoints as a DLL alongside legitimate executable files for antivirus software such as Norton Antivirus, Bkav Antivirus, and IObit Malware Fighter. This pattern of activity indicates that the attacker relied on DLL side-loading via legitimate antivirus software to execute their payloads. Salt Typhoon and similar groups have a history of employing this technique [4][5], enabling them to execute payloads under the guise of trusted software and bypassing traditional security controls.

Command-and-Control (C2)

The backdoor delivered by the threat actor leveraged LightNode VPS endpoints for C2, communicating over both HTTP and an unidentified TCP-based protocol. This dual-channel setup is consistent with Salt Typhoon’s known use of non-standard and layered protocols to evade detection. The HTTP communications displayed by the backdoor included POST requests with an Internet Explorer User-Agent header and Target URI patterns such as “/17ABE7F017ABE7F0”. One of the C2 hosts contacted by compromised endpoints was aar.gandhibludtric[.]com (38.54.63[.]75), a domain recently linked to Salt Typhoon [6].

Detection timeline

Darktrace produced high confidence detections in response to the early stages of the intrusion, with both the initial tooling and C2 activities being strongly covered by both investigations by Darktrace Cyber AI AnalystTM investigations and Darktrace models. Despite the sophistication of the threat actor, the intrusion activity identified and remediated before escalating beyond these early stages of the attack, with Darktrace’s timely high-confidence detections likely playing a key role in neutralizing the threat.

Cyber AI Analyst observations

Darktrace’s Cyber AI Analyst autonomously investigated the model alerts generated by Darktrace during the early stages of the intrusion. Through its investigations, Cyber AI Analyst discovered the initial tooling and C2 events and pieced them together into unified incidents representing the attacker’s progression.

Cyber AI Analyst weaved together separate events from the intrusion into broader incidents summarizing the attacker’s progression.
Figure 1: Cyber AI Analyst weaved together separate events from the intrusion into broader incidents summarizing the attacker’s progression.

Conclusion

Based on overlaps in TTPs, staging patterns, infrastructure, and malware, Darktrace assesses with moderate confidence that the observed activity was consistent with Salt Typhoon/Earth Estries (ALA GhostEmperor/UNC2286). Salt Typhoon continues to challenge defenders with its stealth, persistence, and abuse of legitimate tools. As attackers increasingly blend into normal operations, detecting behavioral anomalies becomes essential for identifying subtle deviations and correlating disparate signals. The evolving nature of Salt Typhoon’s tradecraft, and its ability to repurpose trusted software and infrastructure, ensures it will remain difficult to detect using conventional methods alone. This intrusion highlights the importance of proactive defense, where anomaly-based detections, not just signature matching, play a critical role in surfacing early-stage activity.

Credit to Nathaniel Jones (VP, Security & AI Strategy, FCISO), Sam Lister (Specialist Security Researcher), Emma Foulger (Global Threat Research Operations Lead), Adam Potter (Senior Cyber Analyst)

Edited by Ryan Traill (Analyst Content Lead)

Appendices

Indicators of Compromise (IoCs)

IoC-Type-Description + Confidence

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 TTPs

Technique | Description

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

Darktrace Model Alerts during intrusion

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  

References

[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/

The content provided in this blog is published by Darktrace for general informational purposes only and reflects our understanding of cybersecurity topics, trends, incidents, and developments at the time of publication. While we strive to ensure accuracy and relevance, the information is provided “as is” without any representations or warranties, express or implied. Darktrace makes no guarantees regarding the completeness, accuracy, reliability, or timeliness of any information presented and expressly disclaims all warranties.

Nothing in this blog constitutes legal, technical, or professional advice, and readers should consult qualified professionals before acting on any information contained herein. Any references to third-party organizations, technologies, threat actors, or incidents are for informational purposes only and do not imply affiliation, endorsement, or recommendation.

Darktrace, its affiliates, employees, or agents shall not be held liable for any loss, damage, or harm arising from the use of or reliance on the information in this blog.

The cybersecurity landscape evolves rapidly, and blog content may become outdated or superseded. We reserve the right to update, modify, or remove any content.

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Nathaniel Jones
VP, Security & AI Strategy, Field CISO

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October 15, 2025

How a Major Civil Engineering Company Reduced MTTR across Network, Email and the Cloud with Darktrace

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Asking more of the information security team

“What more can we be doing to secure the company?” is a great question for any cyber professional to hear from their Board of Directors. After successfully defeating a series of attacks and seeing the potential for AI tools to supercharge incoming threats, a UK-based civil engineering company’s security team had the answer: Darktrace.

“When things are coming at you at machine speed, you need machine speed to fight it off – it’s as simple as that,” said their Information Security Manager. “There were incidents where it took us a few hours to get to the bottom of what was going on. Darktrace changed that.”

Prevention was also the best cure. A peer organization in the same sector was still in business continuity measures 18 months after an attack, and the security team did not want to risk that level of business disruption.

Legacy tools were not meeting the team’s desired speed or accuracy

The company’s native SaaS email platform took between two and 14 days to alert on suspicious emails, with another email security tool flagging malicious emails after up to 24 days. After receiving an alert, responses often took a couple of days to coordinate. The team was losing precious time.

Beyond long detection and response times, the old email security platform was no longer performing: 19% of incoming spam was missed. Of even more concern: 6% of phishing emails reached users’ inboxes, and malware and ransomware email was also still getting through, with 0.3% of such email-borne payloads reaching user inboxes.

Choosing Darktrace

“When evaluating tools in 2023, only Darktrace had what I was looking for: an existing, mature, AI-based cybersecurity solution. ChatGPT had just come out and a lot of companies were saying ‘AI this’ and ‘AI that’. Then you’d take a look, and it was all rules- and cases-based, not AI at all,” their Information Security Manager.

The team knew that, with AI-enabled attacks on the horizon, a cybersecurity company that had already built, fielded, and matured an AI-powered cyber defense would give the security team the ability to fend off machine-speed attacks at the same pace as the attackers.

Darktrace accomplishes this with multi-layered AI that learns each organization’s normal business operations. With this detailed level of understanding, Darktrace’s Self-Learning AI can recognize unusual activity that may indicate a cyber-attack, and works to neutralize the threat with precise response actions. And it does this all at machine speed and with minimal disruption.

On the morning the team was due to present its findings, the session was cancelled – for a good reason. The Board didn’t feel further discussion was necessary because the case for Darktrace was so conclusive. The CEO described the Darktrace option as ‘an insurance policy we can’t do without’.

Saving time with Darktrace / EMAIL

Darktrace / EMAIL reduced the discovery, alert, and response process from days or weeks to seconds .

Darktrace / EMAIL automates what was originally a time-consuming and repetitive process. The team has recovered between eight and 10 working hours a week by automating much of this process using / EMAIL.

Today, Darktrace / EMAIL prevents phishing emails from reaching employees’ inboxes. The volume of hostile and unsolicited email fell to a third of its original level after Darktrace / EMAIL was set up.

Further savings with Darktrace / NETWORK and Darktrace / IDENTITY

Since its success with Darktrace / EMAIL, the company adopted two more products from the Darktrace ActiveAI Security Platform – Darktrace / NETWORK and Darktrace / IDENTITY.

These have further contributed to cost savings. An initial plan to build a 24/7 SOC would have required hiring and retaining six additional analysts, rather than the two that currently use Darktrace, costing an additional £220,000 per year in salary. With Darktrace, the existing analysts have the tools needed to become more effective and impactful.

An additional benefit: Darktrace adoption has lowered the company’s cyber insurance premiums. The security team can reallocate this budget to proactive projects.

Detection of novel threats provides reassurance

Darktrace’s unique approach to cybersecurity added a key benefit. The team’s previous tool took a rules-based approach – which was only good if the next attack featured the same characteristics as the ones on which the tool was trained.

“Darktrace looks for anomalous behavior, and we needed something that detected and responded based on use cases, not rules that might be out of date or too prescriptive,” their Information Security Manager. “Our existing provider could take a couple of days to update rules and signatures, and in this game, speed is of the essence. Darktrace just does everything we need - without delay.”

Where rules-based tools must wait for a threat to emerge before beginning to detect and respond to it, Darktrace identifies and protects against unknown and novel threats, speeding identification, response, and recovery, minimizing business disruption as a result.

Looking to the future

With Darktrace in place, the UK-based civil engineering company team has reallocated time and resources usually spent on detection and alerting to now tackle more sophisticated, strategic challenges. Darktrace has also equipped the team with far better and more regularly updated visibility into potential vulnerabilities.

“One thing that frustrates me a little is penetration testing; our ISO accreditation mandates a penetration test at least once a year, but the results could be out of date the next day,” their Information Security Manager. “Darktrace / Proactive Exposure Management will give me that view in real time – we can run it daily if needed - and that’s going to be a really effective workbench for my team.”

As the company looks to further develop its security posture, Darktrace remains poised to evolve alongside its partner.

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