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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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March 11, 2026

NetSupport RAT: How Legitimate Tools Can Be as Damaging as Malware

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What is NetSupport Manager?

NetSupport Manager is a legitimate IT tool used by system administrators for remote support, monitoring, and management. In use since 1989, NetSupport Manager enables users to remotely access and navigate systems across different platforms and operating systems [1].

What is NetSupport RAT?

Although NetSupport Manager is a legitimate tool that can be used by IT and security professionals, there has been a rising number of cases in which it is abused to gain unauthorized access to victim systems. This misuse has become so prevalent that, in recent years, security researchers have begun referring to NetSupport as a Remote Access Trojan (RAT), a term typically used for malware that enables a threat actor to remotely access or control an infected device [2][3][4].

NetSupport RAT activity summary

The initial stages of NetSupport RAT infection may vary depending on the source of the initial compromise. Using tactics such as the social engineering tactic ClickFix, threat actors attempt to trick users into inadvertently executing malicious PowerShell commands under the guise of resolving a non-existent issue or completing a fake CAPTCHA verification [5]. Other attack vectors such as phishing emails, fake browser updates, malicious websites, search engine optimization (SEO) poisoning, malvertising and drive-by downloads are also employed to direct users to fraudulent pages and fake reCAPTCHA verification checks, ultimately inducing them to execute malicious PowerShell commands [5][6][7]. This leads to the successful installation of NetSupport Manager on the compromised device, which is often placed in non-standard directories such as AppData, ProgramData, or Downloads [3][8].

Once installed, the adversary is able to gain remote access to the affected machine, monitor user activity, exfiltrate data, communicate with the command-and-control (C2) server, and maintain persistence [5]. External research has also highlighted that post-exploitation of NetSupport RAT has involved the additional download of malicious payloads [2][5].

Attack flow diagram highlighting key events across each phase of the attack phase
Figure 1: Attack flow diagram highlighting key events across each phase of the attack phase [2][5].

Darktrace coverage

In November of 2025, suspicious behavior indicative of the malicious abuse of NetSupport Manager was observed on multiple customers across Europe, the Middle East, and Africa (EMEA) and the Americas (AMS).

While open-source intelligence (OSINT) has reported that, in a recent campaign, a threat actor impersonated government entities to trick users in organizations in the Information Technology, Government and Financial Services sectors in Central Asia into downloading NetSupport Manager [8], approximately a third of Darktrace’s affected customers in November were based in the US while the rest were based in EMEA. This contrast underscores how widely NetSupport Manager is leveraged by threat actors and highlights its accessibility as an initial access tool.  

The Darktrace customers affected were in sectors including Information and Communication, Manufacturing and Arts, entertainment and recreation.

The ClickFix social engineering tactic typically used to distribute the NetSupport RAT is known to target multiple industries, including Technology, Manufacturing and Energy sectors [9]. It also reflects activity observed in the campaign targeting Central Asia, where the Information Technology sector was among those affected [8].

The prevalence of affected Education customers highlights NetSupport’s marketing focus on the Education sector [10]. This suggests that threat actors are also aware of this marketing strategy and have exploited the trust it creates to deploy NetSupport Manager and gain access to their targets’ systems. While the execution of the PowerShell commands that led to the installation of NetSupport Manager falls outside of Darktrace's purview in cases identified, Darktrace was still able to identify a pattern of devices making connections to multiple rare external domains and IP addresses associated with the NetSupport RAT, using a wide range of ports over the HTTP protocol. A full list of associated domains and IP addresses is provided in the Appendices of this blog.

Although OSINT identifies multiple malicious domains and IP addresses as used as C2 servers, signature-based detections of NetSupport RAT indicators of compromise (IoCs) may miss broader activity, as new malicious websites linked to the RAT continue to appear.

Darktrace’s anomaly‑based approach allows it to establish a normal ‘pattern of life’ for each device on a network and identify when behavior deviates from this baseline, enabling the detection of unusual activity even when it does not match known IoCs or tactics, techniques and procedures (TTPs).

In one customer environment in late 2025, Darktrace / NETWORK detected a device initiating new connections to the rare external endpoint, thetavaluemetrics[.]com (74.91.125[.]57), along with the use of a previously unseen user agent, which it recognized as highly unusual for the network.

Darktrace’s detection of HTTP POST requests to a suspicious URI and new user agent usage.
Figure 2: Darktrace’s detection of HTTP POST requests to a suspicious URI and new user agent usage.

Darktrace identified that user agent present in connections to this endpoint was the ‘NetSupport Manager/1.3’, initially suggesting legitimate NetSupport Manager activity. Subsequent investigation, however, revealed that the endpoint was in fact a malicious NetSupportRAT C2 endpoint [12]. Shortly after, Darktrace detected the same device performing HTTP POST requests to the URI fakeurl[.]htm. This pattern of activity is consistent with OSINT reporting that details communication between compromised devices and NetSupport Connectivity Gateways functioning as C2 servers [11].

Conclusion

As seen not only with NetSupport Manager but with any legitimate or open‑source software used by IT and security professionals, the legitimacy of a tool does not prevent it from being abused by threat actors. Open‑source software, especially tools with free or trial versions such as NetSupport Manager, remains readily accessible for malicious use, including network compromise. In an age where remote work is still prevalent, validating any anomalous use of software and remote management tools is essential to reducing opportunities for unauthorized access.

Darktrace’s anomaly‑based detection enables security teams to identify malicious use of legitimate tools, even when clear signatures or indicators of compromise are absent, helping to prevent further impact on a network.


Credit to George Kim (Analyst Consulting Lead – AMS), Anna Gilbertson (Senior Cyber Analyst)

Edited by Ryan Traill (Analyst Content Lead)

Appendices

Darktrace Model Alerts

·       Compromise / Suspicious HTTP and Anomalous Activity

·       Compromise / New User Agent and POST

·       Device / New User Agent

·       Anomalous Connection / New User Agent to IP Without Hostname

·       Anomalous Connection / Posting HTTP to IP Without Hostname

·       Anomalous Connection / Multiple Failed Connections to Rare Endpoint

·       Anomalous Connection / Application Protocol on Uncommon Port

·       Anomalous Connection / Multiple HTTP POSTs to Rare Hostname

·       Compromise / Beaconing Activity To External Rare

·       Compromise / HTTP Beaconing to Rare Destination

·       Compromise / Agent Beacon (Medium Period)

·       Compromise / Agent Beacon (Long Period)

·       Compromise / Quick and Regular Windows HTTP Beaconing

·       Compromise / Sustained TCP Beaconing Activity To Rare Endpoint

·       Compromise / POST and Beacon to Rare External

Indicators of Compromise (IoCs)

Indicator           Type     Description

/fakeurl.htm URI            NetSupportRAT C2 URI

thetavaluemetrics[.]com        Connection hostname              NetSupportRAT C2 Endpoint

westford-systems[.]icu            Connection hostname              NetSupportRAT C2 Endpoint

holonisz[.]com                Connection hostname              NetSupportRAT C2 Endpoint

heaveydutyl[.]com      Connection hostname              NetSupportRAT C2 Endpoint

nsgatetest1[.]digital   Connection hostname              NetSupportRAT C2 Endpoint

finalnovel[.]com            Connection hostname              NetSupportRAT C2 Endpoint

217.91.235[.]17              IP             NetSupportRAT C2 Endpoint

45.94.47[.]224                 IP             NetSupportRAT C2 Endpoint

74.91.125[.]57                 IP             NetSupportRAT C2 Endpoint

88.214.27[.]48                 IP             NetSupportRAT C2 Endpoint

104.21.40[.]75                 IP             NetSupportRAT C2 Endpoint

38.146.28[.]242              IP             NetSupportRAT C2 Endpoint

185.39.19[.]233              IP             NetSupportRAT C2 Endpoint

45.88.79[.]237                 IP             NetSupportRAT C2 Endpoint

141.98.11[.]224              IP             NetSupportRAT C2 Endpoint

88.214.27[.]166              IP             NetSupportRAT C2 Endpoint

107.158.128[.]84          IP             NetSupportRAT C2 Endpoint

87.120.93[.]98                 IP             Rhadamanthys C2 Endpoint

References

  1. https://mspalliance.com/netsupport-debuts-netsupport-24-7/
  2. https://blogs.vmware.com/security/2023/11/netsupport-rat-the-rat-king-returns.html
  3. https://redcanary.com/threat-detection-report/threats/netsupport-manager/
  4. https://www.elastic.co/guide/en/security/8.19/netsupport-manager-execution-from-an-unusual-path.html
  5. https://rewterz.com/threat-advisory/netsupport-rat-delivered-through-spoofed-verification-pages-active-iocs
  6. https://thehackernews.com/2025/11/new-evalusion-clickfix-campaign.html
  7. https://corelight.com/blog/detecting-netsupport-manager-abuse
  8. https://thehackernews.com/2025/11/bloody-wolf-expands-java-based.html
  9. https://unit42.paloaltonetworks.com/preventing-clickfix-attack-vector
  10. https://www.netsupportsoftware.com/education-solutions
  11. https://www.esentire.com/blog/unpacking-netsupport-rat-loaders-delivered-via-clickfix
  12. https://threatfox.abuse.ch/browse/malware/win.netsupportmanager_rat/
  13. https://www.virustotal.com/gui/url/5fe6936a69c786c9ded9f31ed1242c601cd64e1d90cecd8a7bb03182c47906c2

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About the author
George Kim
Analyst Consulting Lead – AMS

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March 5, 2026

Inside Cloud Compromise: Investigating Attacker Activity with Darktrace / Forensic Acquisition & Investigation

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Investigating Cloud Attacks with Forensic Acquisition & Investigation

Darktrace / Forensic Acquisition & Investigation™ is the industry’s first truly automated forensic solution purpose-built for the cloud. This blog will demonstrate how an investigation can be carried out against a compromised cloud server in minutes, rather than hours or days.

The compromised server investigated in this case originates from Darktrace’s Cloudypots system, a global honeypot network designed to observe adversary activity in real time across a wide range of cloud services. Whenever an attacker successfully compromises one of these honeypots, a forensic copy of the virtual server's disk is preserved for later analysis. Using Forensic Acquisition & Investigation, analysts can then investigate further and obtain detailed insights into the compromise including complete attacker timelines and root cause analysis.

Forensic Acquisition & Investigation supports importing artifacts from a variety of sources, including EC2 instances, ECS, S3 buckets, and more. The Cloudypots system produces a raw disk image whenever an attack is detected and stores it in an S3 bucket. This allows the image to be directly imported into Forensic Acquisition & Investigation using the S3 bucket import option.

As Forensic Acquisition & Investigation runs cloud-natively, no additional configuration is required to add a specific S3 bucket. Analysts can browse and acquire forensic assets from any bucket that the configured IAM role is permitted to access. Operators can also add additional IAM credentials, including those from other cloud providers, to extend access across multiple cloud accounts and environments.

Figure 1: Forensic Acquisition & Investigation import screen.

Forensic Acquisition & Investigation then retrieves a copy of the file and automatically begins running the analysis pipeline on the artifact. This pipeline performs a full forensic analysis of the disk and builds a timeline of the activity that took place on the compromised asset. By leveraging Forensic Acquisition & Investigation’s cloud-native analysis system, this process condenses hour of manual work into just minutes.

Successful import of a forensic artifact and initiation of the analysis pipeline.
Figure 2: Successful import of a forensic artifact and initiation of the analysis pipeline.

Once processing is complete, the preserved artifact is visible in the Evidence tab, along with a summary of key information obtained during analysis, such as the compromised asset’s hostname, operating system, cloud provider, and key event count.

The Evidence overview showing the acquired disk image.
Figure 3: The Evidence overview showing the acquired disk image.

Clicking on the “Key events” field in the listing opens the timeline view, automatically filtered to show system- generated alarms.

The timeline provides a chronological record of every event that occurred on the system, derived from multiple sources, including:

  • Parsed log files such as the systemd journal, audit logs, application specific logs, and others.
  • Parsed history files such as .bash_history, allowing executed commands to be shown on the timeline.
  • File-specific events, such as files being created, accessed, modified, or executables being run, etc.

This approach allows timestamped information and events from multiple sources to be aggregated and parsed into a single, concise view, greatly simplifying the data review process.

Alarms are created for specific timeline events that match either a built-in system rule, curated by Darktrace’s Threat Research team or an operator-defined created at the project level. These alarms help quickly filter out noise and highlight on events of interest, such as the creation of a file containing known malware, access to sensitive files like Amazon Web Service (AWS) credentials, suspicious arguments or commands, and more.

 The timeline view filtered to alarm_severity: “1” OR alarm_severity: “3”, showing only events that matched an alarm rule.
Figure 4: The timeline view filtered to alarm_severity: “1” OR alarm_severity: “3”, showing only events that matched an alarm rule.

In this case, several alarms were generated for suspicious Base64 arguments being passed to Selenium. Examining the event data, it appears the attacker spawned a Selenium Grid session with the following payload:

"request.payload": "[Capabilities {browserName: chrome, goog:chromeOptions: {args: [-cimport base64;exec(base64...], binary: /usr/bin/python3, extensions: []}, pageLoadStrategy: normal}]"

This is a common attack vector for Selenium Grid. The chromeOptions object is intended to specify arguments for how Google Chrome should be launched; however, in this case the attacker has abused the binary field to execute the Python3 binary instead of Chrome. Combined with the option to specify command-line arguments, the attacker can use Python3’s -c option to execute arbitrary Python code, in this instance, decoding and executing a Base64 payload.

Selenium’s logs truncate the Arguments field automatically, so an alternate method is required to retrieve the full payload. To do this, the search bar can be used to find all events that occurred around the same time as this flagged event.

Pivoting off the previous event by filtering the timeline to events within the same window using timestamp: [“2026-02-18T09:09:00Z” TO “2026-02-18T09:12:00Z”].
Figure 5: Pivoting off the previous event by filtering the timeline to events within the same window using timestamp: [“2026-02-18T09:09:00Z” TO “2026-02-18T09:12:00Z”].

Scrolling through the search results, an entry from Java’s systemd journal can be identified. This log contains the full, unaltered payload. GCHQ’s CyberChef can then be used to decode the Base64 data into the attacker’s script, which will ultimately be executed.[NJ9]

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About the author
Nathaniel Bill
Malware Research Engineer
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