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Antino

malware · malware:antino single-source

Jewelbug's Windows backdoor, delivered through malicious HTML Application downloaders themed on current geopolitical events and as a fake Adobe Flash or Adobe installer downloaded from group-controlled domains. It uses the Microsoft Graph API as its command-and-control channel so its traffic sits inside legitimate Microsoft cloud services, and on installation it side-loads the group's 'PDF Viewer' browser extension into the victim's browser profile, drops the native-messaging helper and writes the registry value that enables it (Symantec Threat Hunter Team, 2026-08-13).

Coverage
3
first 2026-08-16 → last 2026-11-12
Latest activity
2026-11-12
Unit 42: Falcon C2 runs inside the browser, fed by a script tag in government webmail such as Roundcube
Peak priority
high
1 high · 2 notable
Targets
public-sector
sectors: public-sector, defense, telco · regions: apac, middle-east
Sources cited
5
5 hosts

Defender insights

What each entry about Antino tells a defender to do, newest first.

2026-11-12NOTABLEUnit 42: Falcon C2 runs inside the browser, fed by a script tag in government webmail such as Roundcube

Exposure · triage · detection

2026-10-02NOTABLETalos: Antino's traffic ends only at Microsoft's Graph and login endpoints, so network telemetry shows only Microsoft

Exposure · triage · detection

2026-08-16HIGHA hack-for-hire group hit 15+ government webmail tenants with one script tag, then escaped the browser via a fake Edge helper

Triage

Relationships explore in graph

Typed, source-stated connections from the entity registry; each edge cites the entry whose reporting establishes it.

used by

Story timeline

  1. 2026-11-12Falcon: Unit 42 describes a browser-resident command-and-control framework planted in government webmail and web applications, with a script tag in Roundcube at a Middle Eastern foreign ministry and a sideloaded 'PDF Viewer' extension elsewhere; it shares its core with PeckBirdy
    active-threatsUnit 42: Falcon C2 runs inside the browser, fed by a script tag in government webmail such as Roundcube
  2. 2026-10-02UAT-11587: a China-nexus cluster spear-phishes Asian government and policy bodies with Antino, a Rust backdoor whose only command channel is Microsoft 365 through Microsoft Graph
    active-threatsTalos: Antino's traffic ends only at Microsoft's Graph and login endpoints, so network telemetry shows only Microsoft
  3. 2026-08-16Jewelbug: one script tag in a shared government webmail template put a watering hole on 15+ ministry tenants at once, and the browser extension it drops escapes the sandbox through a native-messaging host named after Microsoft Edge
    deep-diveA hack-for-hire group hit 15+ government webmail tenants with one script tag, then escaped the browser via a fake Edge helper
ATT&CK techniques (32 across 12 tactics)

32 techniques observed across 3 entries about this entity, derived from entry metadata and body evidence, never asserted without a published entry behind it · pinned to MITRE ATT&CK v20.1 · compare on the matrix · Navigator layer (JSON)

  • Resource DevelopmentAcquire Infrastructure: Web Services
  • Initial AccessDrive-by Compromise · Phishing: Spearphishing Link
  • ExecutionCommand and Scripting Interpreter: PowerShell · Command and Scripting Interpreter: Windows Command Shell · Command and Scripting Interpreter: JavaScript · User Execution: Malicious File · Hijack Execution Flow: DLL
  • PersistenceSoftware Extensions: Browser Extensions · Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder · Modify Authentication Process: Pluggable Authentication Modules
  • Privilege EscalationBoot or Logon Autostart Execution: Registry Run Keys / Startup Folder
  • StealthRootkit · Obfuscated Files or Information · Masquerading: Match Legitimate Resource Name or Location · Deobfuscate/Decode Files or Information · System Binary Proxy Execution: Mshta · Hijack Execution Flow: DLL · Reflective Code Loading · Social Engineering: Email Spoofing
  • Defense ImpairmentModify Authentication Process: Pluggable Authentication Modules
  • Credential AccessInput Capture: Web Portal Capture · Steal Web Session Cookie · Modify Authentication Process: Pluggable Authentication Modules
  • DiscoverySystem Information Discovery · File and Directory Discovery
  • CollectionInput Capture: Web Portal Capture · Screen Capture · Clipboard Data · Browser Session Hijacking
  • Command and ControlApplication Layer Protocol: Web Protocols · Proxy · Web Service: Dead Drop Resolver · Web Service: Bidirectional Communication · Ingress Tool Transfer · Encrypted Channel: Asymmetric Cryptography
  • ExfiltrationExfiltration Over C2 Channel

Resource Development TA0042

T1583.006Acquire Infrastructure: Web Services×1

Adversaries may register for web services that can be used during targeting. A variety of popular websites exist for adversaries to register for a web-based service that can be abused during later stages of the adversary lifecycle, such as during Command and Control (Web Service), Exfiltration Over Web Service, or Phishing. Using common services, such as those offered by Google, GitHub, or Twitter, makes it easier for adversaries to hide in expected noise. By utilizing a web service, adversaries can make it difficult to physically tie back operations to them.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Initial Access TA0001

T1189Drive-by Compromise×2

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing. Multiple ways of delivering exploit code to a browser exist (i.e., Drive-by Target), including:

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1566.002Phishing: Spearphishing Link×1

Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems. Spearphishing with a link is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of links to download malware contained in email, instead of attaching malicious files to the email itself, to avoid defenses that may inspect email attachments. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Execution TA0002

T1059.001Command and Scripting Interpreter: PowerShell×1

Adversaries may abuse PowerShell commands and scripts for execution. PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system. PowerShell can also be installed on Linux and macOS. Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the <code>Start-Process</code> cmdlet which can be used to run an executable and the <code>Invoke-Command</code> cmdlet which runs a command locally or on a remote computer (though administrator permissions are required to use PowerShell to connect to remote systems).

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1059.003Command and Scripting Interpreter: Windows Command Shell×2

Adversaries may abuse the Windows command shell for execution. The Windows command shell (cmd) is the primary command prompt on Windows systems. The Windows command prompt can be used to control almost any aspect of a system, with various permission levels required for different subsets of commands. The command prompt can be invoked remotely via Remote Services such as SSH.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1059.007Command and Scripting Interpreter: JavaScript×1

Adversaries may abuse various implementations of JavaScript for execution. JavaScript (JS) is a platform-independent scripting language (compiled just-in-time at runtime) commonly associated with scripts in webpages, though JS can be executed in runtime environments outside the browser.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1204.002User Execution: Malicious File×3

An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from Spearphishing Attachment. Adversaries may use several types of files that require a user to execute them, including .doc, .pdf, .xls, .rtf, .scr, .exe, .lnk, .pif, .cpl, .reg, and .iso.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1574.001Hijack Execution Flow: DLL×1

Adversaries may abuse dynamic-link library files (DLLs) in order to achieve persistence, escalate privileges, and evade defenses. DLLs are libraries that contain code and data that can be simultaneously utilized by multiple programs. While DLLs are not malicious by nature, they can be abused through mechanisms such as side-loading, hijacking search order, and phantom DLL hijacking.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Persistence TA0003

T1176.001Software Extensions: Browser Extensions×2

Adversaries may abuse internet browser extensions to establish persistent access to victim systems. Browser extensions or plugins are small programs that can add functionality to and customize aspects of internet browsers. They can be installed directly via a local file or custom URL or through a browser's app store - an official online platform where users can browse, install, and manage extensions for a specific web browser. Extensions generally inherit the web browser's permissions previously granted.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1547.001Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder×2

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1556.003Modify Authentication Process: Pluggable Authentication Modules×1

Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is <code>pam_unix.so</code>, which retrieves, sets, and verifies account authentication information in <code>/etc/passwd</code> and <code>/etc/shadow</code>.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

Privilege Escalation TA0004

T1547.001Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder×2

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Stealth TA0005

T1014Rootkit×1

Adversaries may use rootkits to hide the presence of programs, files, network connections, services, drivers, and other system components. Rootkits are programs that hide the existence of malware by intercepting/hooking and modifying operating system API calls that supply system information.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1027Obfuscated Files or Information×2

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1036.005Masquerading: Match Legitimate Resource Name or Location×1

Adversaries may match or approximate the name or location of legitimate files, Registry keys, or other resources when naming/placing them. This is done for the sake of evading defenses and observation.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · ATT&CK page ↗

T1140Deobfuscate/Decode Files or Information×1

Adversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware or by using utilities present on the system.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1218.005System Binary Proxy Execution: Mshta×1

Adversaries may abuse mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1574.001Hijack Execution Flow: DLL×1

Adversaries may abuse dynamic-link library files (DLLs) in order to achieve persistence, escalate privileges, and evade defenses. DLLs are libraries that contain code and data that can be simultaneously utilized by multiple programs. While DLLs are not malicious by nature, they can be abused through mechanisms such as side-loading, hijacking search order, and phantom DLL hijacking.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1620Reflective Code Loading×1

Adversaries may reflectively load code into a process in order to conceal the execution of malicious payloads. Reflective loading involves allocating then executing payloads directly within the memory of the process, vice creating a thread or process backed by a file path on disk (e.g., Shared Modules).

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1684.002Social Engineering: Email Spoofing×1

Adversaries may fake, or spoof, a sender’s identity by modifying the value of relevant email headers in order to establish contact with victims under false pretenses. In addition to actual email content, email headers (such as the FROM header, which contains the email address of the sender) may also be modified. Email clients display these headers when emails appear in a victim's inbox, which may cause modified emails to appear as if they were from the spoofed entity.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Defense Impairment TA0112

T1556.003Modify Authentication Process: Pluggable Authentication Modules×1

Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is <code>pam_unix.so</code>, which retrieves, sets, and verifies account authentication information in <code>/etc/passwd</code> and <code>/etc/shadow</code>.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

Credential Access TA0006

T1056.003Input Capture: Web Portal Capture×2

Adversaries may install code on externally facing portals, such as a VPN login page, to capture and transmit credentials of users who attempt to log into the service. For example, a compromised login page may log provided user credentials before logging the user in to the service.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1539Steal Web Session Cookie×2

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials. Web applications and services often use session cookies as an authentication token after a user has authenticated to a website.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1556.003Modify Authentication Process: Pluggable Authentication Modules×1

Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is <code>pam_unix.so</code>, which retrieves, sets, and verifies account authentication information in <code>/etc/passwd</code> and <code>/etc/shadow</code>.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

Discovery TA0007

T1082System Information Discovery×1

An adversary may attempt to get detailed information about the operating system and hardware, including version, patches, hotfixes, service packs, and architecture. Adversaries may use this information to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions. This behavior is distinct from Local Storage Discovery which is an adversary's discovery of local drive, disks and/or volumes.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1083File and Directory Discovery×1

Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system. Adversaries may use the information from File and Directory Discovery during automated discovery to shape follow-on behaviors, including whether or not the adversary fully infects the target and/or attempts specific actions.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Collection TA0009

T1056.003Input Capture: Web Portal Capture×2

Adversaries may install code on externally facing portals, such as a VPN login page, to capture and transmit credentials of users who attempt to log into the service. For example, a compromised login page may log provided user credentials before logging the user in to the service.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1113Screen Capture×2

Adversaries may attempt to take screen captures of the desktop to gather information over the course of an operation. Screen capturing functionality may be included as a feature of a remote access tool used in post-compromise operations. Taking a screenshot is also typically possible through native utilities or API calls, such as <code>CopyFromScreen</code>, <code>xwd</code>, or <code>screencapture</code>.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1115Clipboard Data×1

Adversaries may collect data stored in the clipboard from users copying information within or between applications.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1185Browser Session Hijacking×2

Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

Command and Control TA0011

T1071.001Application Layer Protocol: Web Protocols×1

Adversaries may communicate using application layer protocols associated with web traffic to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · ATT&CK page ↗

T1090Proxy×1

Adversaries may use a connection proxy to direct network traffic between systems or act as an intermediary for network communications to a command and control server to avoid direct connections to their infrastructure. Many tools exist that enable traffic redirection through proxies or port redirection, including HTRAN, ZXProxy, and ZXPortMap. Adversaries use these types of proxies to manage command and control communications, reduce the number of simultaneous outbound network connections, provide resiliency in the face of connection loss, or to ride over existing trusted communications paths between victims to avoid suspicion. Adversaries may chain together multiple proxies to further disguise the source of malicious traffic.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1102.001Web Service: Dead Drop Resolver×1

Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers.

Evidence: 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1102.002Web Service: Bidirectional Communication×3

Adversaries may use an existing, legitimate external Web service as a means for sending commands to and receiving output from a compromised system over the Web service channel. Compromised systems may leverage popular websites and social media to host command and control (C2) instructions. Those infected systems can then send the output from those commands back over that Web service channel. The return traffic may occur in a variety of ways, depending on the Web service being utilized. For example, the return traffic may take the form of the compromised system posting a comment on a forum, issuing a pull request to development project, updating a document hosted on a Web service, or by sending a Tweet.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · 2026-08-16/jewelbug-pdf-viewer-extension-native-messaging-webmail-hole · ATT&CK page ↗

T1105Ingress Tool Transfer×1

Adversaries may transfer tools or other files from an external system into a compromised environment. Tools or files may be copied from an external adversary-controlled system to the victim network through the command and control channel or through alternate protocols such as ftp. Once present, adversaries may also transfer/spread tools between victim devices within a compromised environment (i.e. Lateral Tool Transfer).

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

T1573.002Encrypted Channel: Asymmetric Cryptography×1

Adversaries may employ a known asymmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Asymmetric cryptography, also known as public key cryptography, uses a keypair per party: one public that can be freely distributed, and one private. Due to how the keys are generated, the sender encrypts data with the receiver’s public key and the receiver decrypts the data with their private key. This ensures that only the intended recipient can read the encrypted data. Common public key encryption algorithms include RSA and ElGamal.

Evidence: 2026-11-12/falcon-c2-browser-implant-government-webmail-script-tag · ATT&CK page ↗

Exfiltration TA0010

T1041Exfiltration Over C2 Channel×1

Adversaries may steal data by exfiltrating it over an existing command and control channel. Stolen data is encoded into the normal communications channel using the same protocol as command and control communications.

Evidence: 2026-10-02/uat-11587-antino-microsoft-graph-c2-asian-governments · ATT&CK page ↗

Entries about Antino (3)

2026-11-12 · view entry permalink →

NOTABLENATOB2

Falcon: Unit 42 describes a browser-resident command-and-control framework planted in government webmail and web applications, with a script tag in Roundcube at a Middle Eastern foreign ministry and a sideloaded 'PDF Viewer' extension elsewhere; it shares its core with PeckBirdy

Unit 42 describes Falcon C2, also called XG and not the CrowdStrike Falcon sensor, a NodeJS command-and-control framework whose operator-controlled JavaScript implant runs inside the victim's browser, so the endpoint holds no file for it (Unit 42, 2026-11-11). A script tag placed in a trusted site makes each visit request the implant from the Falcon server, which returns a script obfuscated per browser session, and the implant then holds a TLS WebSocket to the server while the tab is open and runs operator JavaScript through eval (Unit 42, 2026-11-11). Unit 42 identified compromised government entities in one Middle Eastern and four Southeast Asian countries between March and May 2026, among them ministries and law enforcement agencies, and names no actor (Unit 42, 2026-11-11).

In April 2026 a script tag inserted into the Roundcube webmail portal of a Middle Eastern ministry of foreign affairs let the operator intercept credentials as users signed in and monitor sessions (39 Roundcube instances in that country, none observed elsewhere; how the tag got in is not stated) (Unit 42, 2026-11-11). In May 2026 a module in a Southeast Asian police web application harvested usernames and then showed a fake Adobe Flash Player update prompt to chosen users, which served the Antino implant that uses Microsoft OneDrive for command and control (Unit 42, 2026-11-11). Against a justice-department entity in another country, a Chrome extension named PDF Viewer, sideloaded in developer mode, checked in every 3 to 4 minutes for over three weeks and exfiltrated plaintext credentials for an internal correspondence system and a screenshot of a document the victim was viewing (Unit 42, 2026-11-11). The Jewelbug campaign also used an extension named PDF Viewer (Symantec, 2026-08-13); Unit 42 lists it only as a further resource.

Unit 42 assesses with high confidence that Falcon and PeckBirdy (Trend's JScript framework used by China-aligned actors since 2023) are variants of one core framework; that is code lineage, not who operates Falcon (Unit 42, 2026-11-11; Trend Micro, 2026-01-26).

Triage: Unit 42's basis for the cookie check is that Baidu Analytics cookies are normal on sites that use that service and anomalous on internal government web applications where it has no reason to appear (Unit 42, 2026-11-11).

We are currently unaware of how an operator is deploying these browser extensions.

We observed a total of 39 Roundcube instances being affected within the target country.

Based on these extensive technical overlaps, we assess with high confidence that Falcon and PeckBirdy represent variants of the same core framework.

Palo Alto Networks Unit 42 2026-11-11

Builds on: A hack-for-hire group hit 15+ government webmail tenants with one script tag, then escaped the… · Talos: Antino's traffic ends only at Microsoft's Graph and login endpoints, so network…

threat12 Nov 04:05Zsingle-sourceOpen finding →

2026-10-02 · view entry permalink →

NOTABLENATOB2

UAT-11587: a China-nexus cluster spear-phishes Asian government and policy bodies with Antino, a Rust backdoor whose only command channel is Microsoft 365 through Microsoft Graph

Cisco Talos tracks UAT-11587, first seen in September 2025, with at least 10 confirmed and five probable affected institutional environments and about 350 compromised endpoints across eight countries (Taiwan, India, the Philippines, Cambodia, Pakistan, Thailand, Myanmar and Syria, listed at moderate-to-high confidence); the targets include defense, central administration, justice and law enforcement, government IT and e-government services, legislatures and policy research bodies (Cisco Talos, 2026-09-30). Talos assesses China-nexus with high confidence and intelligence gathering with moderate confidence, and notes overlaps with the Antino activity Symantec attributes to Jewelbug without being able to verify a link to Jewelbug's financially motivated activity (Cisco Talos, 2026-09-30).

Delivery is spear-phishing in which the envelope sender is an attacker-controlled domain relayed through Migadu while the visible From header shows the impersonated organization, so SPF passes for the envelope domain, DMARC alignment fails, and a p=none policy on the impersonated domain lets the message reach the inbox; the mail body reproduces Gmail's attachment widget as images linking to a Cloudflare Pages address (Cisco Talos, 2026-09-30). The five-stage chain starts with an HTA stager run by mshta.exe, then a JScript downloader and decryptor that pulls encrypted resources from Cloudflare R2 or CloudFront, then .NET deserialization gadgets that load a downloader assembly inside mshta.exe, which writes a decoy and a three-file bundle and launches the Microsoft-signed Windows ADK binary GatherOsState.exe; that binary sideloads an unexpected DLL, which is Antino (Cisco Talos, 2026-09-30).

Antino is a Rust backdoor whose second-generation build authenticates to Microsoft Graph with the OAuth 2.0 client-credentials flow of an Entra application, polls an Outlook folder every 10 seconds for command emails, sends a OneDrive heartbeat every minute and uses OneDrive folders for tool staging and exfiltration, so outbound traffic ends only at graph.microsoft.com and login.microsoftonline.com (Cisco Talos, 2026-09-30). Its commands run cmd.exe and PowerShell, list, upload and download files, load shellcode in memory and add a registry Run value; execution and persistence abuse the Windows Scripted Diagnostics workflow, in which sdiagnhost.exe runs an attacker-written PowerShell script that writes the HKCU Run value (Cisco Talos, 2026-09-30).

Triage: Microsoft Graph traffic and signed Windows ADK binaries are both normal; the signal is the combination of GatherOsState.exe running from a staging directory outside the Windows ADK install, beside an unexpected DLL and that process then holding Graph connections.

Antino communicates exclusively through Microsoft 365, using the Microsoft Graph API to interact with Outlook and OneDrive as dead-drop C2 channels.

In the reviewed message, the displayed domain used a non-enforcing p=none policy, which requested monitoring rather than quarantine or rejection.

Talos could not independently verify a connection between the espionage campaign and Jewelbug’s financially motivated activity.

Cisco Talos 2026-09-30

Builds on: A hack-for-hire group hit 15+ government webmail tenants with one script tag, then escaped the…

threat02 Oct 04:50Zsingle-sourceOpen finding →
Sources: Cisco Talos

2026-08-16 · view entry permalink →

HIGHNATOB2

Jewelbug: one script tag in a shared government webmail template put a watering hole on 15+ ministry tenants at once, and the browser extension it drops escapes the sandbox through a native-messaging host named after Microsoft Edge

Symantec's Threat Hunter Team has published the results of a months-long investigation into Jewelbug, a China-based hack-for-hire group that runs two missions from one set of hands: espionage against government ministries and militaries across the Middle East, Southeast Asia and South Asia, and a for-profit cryptocurrency-fraud business aimed at Chinese-speaking victims. Both are administered from a single control panel called XG-Web, a browser-centric remote-access and information-stealing framework built as a React panel over a Node.js backend with a MySQL database that doubles as the rendezvous point for victim implants; its developers describe it in their own documentation as a "penetration-testing platform", while its internal function names include browser hijacking, data theft and man-in-the-middle attack (Symantec, 2026-08-13). Symantec assesses with high confidence that the fraud and search-engine-optimisation arm is run by the sole legal representative of a registered Changsha company, on the basis of government-issued identity documents, a business licence and a signed authorisation letter recovered from the operators, and considers it most likely that the SEO business supplied access, infrastructure and delivery to the espionage operation rather than one person performing both roles (Symantec, 2026-08-13).

The access pattern is the finding. In its largest espionage operation, Jewelbug did not attack ministries individually. It compromised the shared web-hosting platform run by a Middle Eastern state telecommunications provider and national network-services agency, obtained write access to the common webmail installation, and added one script tag, planting a watering hole on every government tenant on that platform at once, in a single campaign that spanned more than 15 tenants (Symantec, 2026-08-13). Symantec infers the tag sat in the shared template rather than being delivered per user because the hook fired on the login page and on every mailbox view. The group also hooked the hosting provider's own administrators to harvest the credentials that granted that write access, which closes the loop: the platform operator's identity was the key to every tenant behind it.

The chain that follows is short and entirely conventional in its parts, which is what makes it worth mapping. When a ministry staff member logged in, the injected script opened a WebSocket to command-and-control, completed a handshake and reported in; a cookie module exfiltrated the page's cookies, and a labelling module read the username straight out of the webmail interface and tagged the new victim with their government email address. Only then did the operators push a lure module, which checked that the address ended in one of nine targeted government domains, that the account was not already compromised, and that the host was Windows, before overlaying a fake Adobe Flash update prompt (Symantec, 2026-08-13). That server-side qualification step is a defensive problem in itself; the malicious behaviour a visiting analyst or a sandbox sees is a cookie read and a WebSocket, because the payload stage never fires for a visitor who fails the filter.

Clicking the prompt downloaded the Antino backdoor, delivered as a fake Adobe Flash or Adobe installer and using the Microsoft Graph API as its command-and-control channel so its traffic sits inside legitimate Microsoft cloud services. Antino also side-loaded the "PDF Viewer" extension into the victim's browser profile, dropped a native-messaging helper and wrote the registry value that enabled it (Symantec, 2026-08-13). The extension is the group's primary implant and requested, in Symantec's words, effectively every dangerous permission the browser exposes, cookies, scripting, debugger access, web-request interception, download monitoring and native messaging across all sites. A background service worker gave the operator a full bridge into the browser API: any Chrome or Firefox function invocable by name, arbitrary JavaScript injected into any page, credentials harvested by hooking login forms, the full cookie jar exfiltrated, live cookie-change events subscribed to so new session tokens are stolen in near real time, plus history, bookmarks, screenshots, clipboard and intercepted traffic. A clipboard module able to swap a copied cryptocurrency address for the attacker's was present and active on victims, but Symantec records that no address-replacement rules were deployed, so the swap was not used during the observed period.

The sandbox escape is the part defenders should take away. To reach the host, the extension talked to a Windows helper registered as a native-messaging host under the misleading name com.microsoft.runedge, which ran operator commands through the Windows command interpreter and returned output to the panel; Antino wrote the enabling registry value under the current user's own hive (Symantec, 2026-08-13). Native messaging is a documented, legitimate browser feature (it is how password managers and document tools talk to their desktop components) and that is precisely why it works here. For at least one victim the bridge carried authenticated traffic to an internal virtualisation-management interface, so browser access became reach into the network behind it.

The group's toolset extends past the browser. Symantec counts 37 builds of a Rust implant the developers call ClientKing, reaching servers and network devices rather than browsers, supporting five command-and-control transports including a custom DNS tunnel, and offering an interactive shell, SOCKS pivoting and the ability to load kernel modules directly from memory; a companion toolkit adds a kernel-module rootkit and a malicious authentication module hooked into su and sudo to steal credentials, across x86-64 servers, ARM64 devices and consumer routers (Symantec, 2026-08-13). For payload delivery the backend created public Google Documents, wrote an obfuscated payload into the body and had implants fetch and execute it, which resolves to Google-owned infrastructure that reputation filtering is unlikely to block, and the group disguised its command-and-control hostnames as typosquats of common web resources such as font services. A scheduled job checked the group's own domains against a public multi-scanner every twelve hours so operators could rotate away from anything flagged.

Scale, in the group's own bookkeeping: the victim database holds more than one million implant check-in rows, more than 580,000 stolen browser cookies, several thousand captured credentials and more than 2,300 exfiltrated email bodies (Symantec, 2026-08-13). Symantec also notes builds configured to beacon through the internal corporate proxy of a major US aerospace and industrial manufacturer, so the tooling is not confined to government estates.

Triage: a native-messaging host registered under HKCU\SOFTWARE\<browser>\NativeMessagingHosts\<reverse-domain-name> is normal on its own, legitimate password managers, document viewers and enterprise agents use this exact mechanism. Three discriminators separate this from that baseline, and they derive from the mechanics the source describes rather than from any indicator: a host name asserting a Microsoft identity while being written per-user under HKCU by a downloaded executable, where a genuine Microsoft browser component arrives through a signed machine-wide installer; the command interpreter appearing with a native-messaging host executable as its parent, a process-lineage pair that legitimate browser-helper traffic does not produce; and an extension whose manifest requests native messaging together with debugger access, web-request interception and all-sites cookie access, a permission combination a document reader has no use for. The extension side-loads into the browser profile rather than arriving from a store, so an extension inventory built only from store IDs will not see it.

Rather than breach each ministry separately, Jewelbug compromised the shared web-hosting platform run by the state telecommunications provider and national network-services agency, obtaining write access to the common webmail installation, and added a single script tag.

A single campaign spanned more than 15 government webmail tenants, with the hook firing on the login page and every mailbox view, indicating it sat in the shared template rather than being delivered per user.

To escape the browser sandbox, the extension talked to a Windows helper registered as a native-messaging host under the misleading name com.microsoft.runedge, which ran operator commands through the Windows command interpreter and returned the output to the panel.

Masquerading as a document reader, it requested effectively every dangerous permission the browser exposes: cookies, scripting, debugger access, web request interception, download monitoring, and native messaging across all sites.

Symantec Threat Hunter Team
threat16 Aug 04:40Zsingle-sourceOpen finding →

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