2026-09-10HIGHexploitedSix espionage clusters ran the identical click-to-SYSTEM exploit kit within days of each other; Proofpoint calls it the same code, not parallel development
Windows ALPC heap-based buffer overflow EoP / AppContainer sandbox escape to SYSTEM (CVSS 7.8), actively exploited zero-day, CISA KEV 2026-09-08, legacy line (Windows 10, Server 2012-2022)
cve · CVE-2026-85880
Coverage
2
first 2026-09-09 → last 2026-09-29
Latest activity
2026-09-27
Six espionage clusters ran the identical click-to-SYSTEM exploit kit within days of each other; Proofpoint…
Peak priority
high
2 high
Targets
public-sector
sectors: public-sector, defense, manufacturing · regions: us, apac
Sources cited
11
9 hosts
Action items (2)
Do-now tasks recorded on the entries about CVE-2026-85880, newest first. Check the date before acting on an older one.
- After confirming Chrome ≥152.0.7977.82 and the September Windows cumulative update are deployed fleet-wide, separately audit installed Chromium extensions requesting broad host/tab/storage permissions and any browser-associated scheduled task created in the days before patching; neither the malicious GemStone extension nor the kit's scheduled-task persistence is removed by the OS/browser patch.2026-09-10CVE-2026-85046 +2
- Deploy the September 2026 cumulative update to every Windows and Windows Server host now: the Update Stack fix (CVE-2026-81963) covers Server 2025 and Windows 11, the ALPC fix (CVE-2026-85880) covers Windows 10 and Server 2012 through 2022, and a mixed estate needs both to close the SYSTEM-escalation exposure.2026-09-09CVE-2026-81963 +1
Defender insights
What each entry about CVE-2026-85880 tells a defender to do, newest first.
Triage
Triage
Story timeline
- 2026-09-10BlueMoon: six separate state-nexus actor clusters independently weaponize a shared Chrome V8 + Windows kernel zero-day chain
- 2026-09-09September 2026 Patch Tuesday: two actively exploited Windows privilege-escalation zero-days (CVE-2026-81963 Update Stack, CVE-2026-85880 ALPC)
Hunting pivots
Affected products
ATT&CK techniques (21 across 10 tactics)
21 techniques observed across 2 entries about this entity, derived from entry metadata and body evidence, never asserted without a published entry behind it · pinned to MITRE ATT&CK v19.2 · compare on the matrix · Navigator layer (JSON)
- Resource DevelopmentAcquire Infrastructure: Domains
- Initial AccessDrive-by Compromise · Phishing: Spearphishing Link
- ExecutionScheduled Task/Job: Scheduled Task · Exploitation for Client Execution · Inter-Process Communication: Component Object Model · Hijack Execution Flow: DLL
- PersistenceScheduled Task/Job: Scheduled Task · Software Extensions
- Privilege EscalationScheduled Task/Job: Scheduled Task · Process Injection · Exploitation for Privilege Escalation
- StealthObfuscated Files or Information · Process Injection · System Binary Proxy Execution: Msiexec · Hijack Execution Flow: DLL
- Defense ImpairmentSubvert Trust Controls: Mark-of-the-Web Bypass
- Credential AccessInput Capture: Keylogging · Steal Web Session Cookie
- CollectionInput Capture: Keylogging · Screen Capture · Clipboard Data
- Command and ControlApplication Layer Protocol: Web Protocols · Application Layer Protocol: DNS · Ingress Tool Transfer · Encrypted Channel: Symmetric Cryptography
Resource Development TA0042
T1583.001Acquire Infrastructure: Domains×1
Adversaries may acquire domains that can be used during targeting. Domain names are the human readable names used to represent one or more IP addresses. They can be purchased or, in some cases, acquired for free.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Initial Access TA0001
T1189Drive-by Compromise×1
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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Execution TA0002
T1053.005Scheduled Task/Job: Scheduled Task×1
Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1203Exploitation for Client Execution×1
Adversaries may exploit software vulnerabilities in client applications to execute code. Vulnerabilities can exist in software due to unsecure coding practices that can lead to unanticipated behavior. Adversaries can take advantage of certain vulnerabilities through targeted exploitation for the purpose of arbitrary code execution. Oftentimes the most valuable exploits to an offensive toolkit are those that can be used to obtain code execution on a remote system because they can be used to gain access to that system. Users will expect to see files related to the applications they commonly used to do work, so they are a useful target for exploit research and development because of their high utility.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1559.001Inter-Process Communication: Component Object Model×1
Adversaries may use the Windows Component Object Model (COM) for local code execution. COM is an inter-process communication (IPC) component of the native Windows application programming interface (API) that enables interaction between software objects, or executable code that implements one or more interfaces. Through COM, a client object can call methods of server objects, which are typically binary Dynamic Link Libraries (DLL) or executables (EXE). Remote COM execution is facilitated by Remote Services such as Distributed Component Object Model (DCOM).
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Persistence TA0003
T1053.005Scheduled Task/Job: Scheduled Task×1
Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1176Software Extensions×1
Adversaries may abuse software extensions to establish persistent access to victim systems. Software extensions are modular components that enhance or customize the functionality of software applications, including web browsers, Integrated Development Environments (IDEs), and other platforms. Extensions are typically installed via official marketplaces, app stores, or manually loaded by users, and they often inherit the permissions and access levels of the host application.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Privilege Escalation TA0004
T1053.005Scheduled Task/Job: Scheduled Task×1
Adversaries may abuse the Windows Task Scheduler to perform task scheduling for initial or recurring execution of malicious code. There are multiple ways to access the Task Scheduler in Windows. The schtasks utility can be run directly on the command line, or the Task Scheduler can be opened through the GUI within the Administrator Tools section of the Control Panel. In some cases, adversaries have used a .NET wrapper for the Windows Task Scheduler, and alternatively, adversaries have used the Windows netapi32 library and Windows Management Instrumentation (WMI) to create a scheduled task. Adversaries may also utilize the Powershell Cmdlet `Invoke-CimMethod`, which leverages WMI class `PS_ScheduledTask` to create a scheduled task via an XML path.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1055Process Injection×1
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges. Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1068Exploitation for Privilege Escalation×2
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Security constructs such as permission levels will often hinder access to information and use of certain techniques, so adversaries will likely need to perform privilege escalation to include use of software exploitation to circumvent those restrictions.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 2026-09-09/windows-september-2026-two-exploited-lpe-zero-days-kev · ATT&CK page ↗
Stealth TA0005
T1027Obfuscated Files or Information×1
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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1055Process Injection×1
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges. Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1218.007System Binary Proxy Execution: Msiexec×1
Adversaries may abuse msiexec.exe to proxy execution of malicious payloads. Msiexec.exe is the command-line utility for the Windows Installer and is thus commonly associated with executing installation packages (.msi). The Msiexec.exe binary may also be digitally signed by Microsoft.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Defense Impairment TA0112
T1553.005Subvert Trust Controls: Mark-of-the-Web Bypass×1
Adversaries may abuse specific file formats to subvert Mark-of-the-Web (MOTW) controls. In Windows, when files are downloaded from the Internet, they are tagged with a hidden NTFS Alternate Data Stream (ADS) named <code>Zone.Identifier</code> with a specific value known as the MOTW. Files that are tagged with MOTW are protected and cannot perform certain actions. For example, starting in MS Office 10, if a MS Office file has the MOTW, it will open in Protected View. Executables tagged with the MOTW will be processed by Windows Defender SmartScreen that compares files with an allowlist of well-known executables. If the file is not known/trusted, SmartScreen will prevent the execution and warn the user not to run it.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Credential Access TA0006
T1056.001Input Capture: Keylogging×1
Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when OS Credential Dumping efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1539Steal Web Session Cookie×1
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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Collection TA0009
T1056.001Input Capture: Keylogging×1
Adversaries may log user keystrokes to intercept credentials as the user types them. Keylogging is likely to be used to acquire credentials for new access opportunities when OS Credential Dumping efforts are not effective, and may require an adversary to intercept keystrokes on a system for a substantial period of time before credentials can be successfully captured. In order to increase the likelihood of capturing credentials quickly, an adversary may also perform actions such as clearing browser cookies to force users to reauthenticate to systems.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1113Screen Capture×1
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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1115Clipboard Data×1
Adversaries may collect data stored in the clipboard from users copying information within or between applications.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1071.004Application Layer Protocol: DNS×1
Adversaries may communicate using the Domain Name System (DNS) application layer protocol 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · 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: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
T1573.001Encrypted Channel: Symmetric Cryptography×1
Adversaries may employ a known symmetric encryption algorithm to conceal command and control traffic rather than relying on any inherent protections provided by a communication protocol. Symmetric encryption algorithms use the same key for plaintext encryption and ciphertext decryption. Common symmetric encryption algorithms include AES, DES, 3DES, Blowfish, and RC4.
Evidence: 2026-09-10/bluemoon-exploit-kit-four-state-actors-chrome-windows-chain · ATT&CK page ↗
Entries about Windows ALPC heap-based buffer overflow EoP / AppContainer sandbox escape to SYSTEM (CVSS 7.8), actively exploited zero-day, CISA KEV 2026-09-08, legacy line (Windows 10, Server 2012-2022) (2)
Co-occurring entities
Derived: referenced by the same focused operational entries (weekly summaries and report roundups don't count); ×N counts the shared entries.
- Microsoft Windows×2
- APT31×1
- BlueMoon×1
- CLEANGULP×1
- GemStone×1
- GhostChrome-X×1
- Google Chrome×1
- Google Chrome V8 out-of-bounds write, exploited in the wild, patched in Chrome 153 (seventh exploited Chrome zero-day of 2026)×1
Where this entity is cited
Source distribution
- msrc.microsoft.com2 (18%)
- volexity.com2 (18%)
- bleepingcomputer.com1 (9%)
- cisa.gov1 (9%)
- proofpoint.com1 (9%)
- security-hub.ncsc.admin.ch1 (9%)
- thehackernews.com1 (9%)
- therecord.media1 (9%)
- other1 (9%)
External references
All cited sources (11)
- msrc.microsoft.comprimaryMicrosoft MSRChttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963
- msrc.microsoft.comprimaryMicrosoft MSRChttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85880
- bleepingcomputer.comBleepingComputerhttps://www.bleepingcomputer.com/news/microsoft/microsoft-september-2026-patch-tuesday-fixes-966-flaws-2-zero-days/
- cisa.govCISAhttps://www.cisa.gov/news-events/alerts/2026/09/08/cisa-adds-four-known-exploited-vulnerabilities-catalog
- proofpoint.comProofpoint Threat Researchhttps://www.proofpoint.com/us/blog/threat-insight/once-bluemoon-multiple-state-aligned-threat-actors-rapidly-adopt-novel-exploit
- security-hub.ncsc.admin.chNCSC Switzerland (GovCERT.ch) Cyber Security Hubhttps://security-hub.ncsc.admin.ch/#/posts/12936
- thehackernews.comThe Hacker Newshttps://thehackernews.com/2026/09/four-spy-groups-used-same-chrome-and.html
- therecord.mediaThe Record (Recorded Future News)https://therecord.media/china-hackers-chrome-browser-zero-day-multiple-groups
- volexity.comVolexityhttps://www.volexity.com/blog/2026/09/09/mind-the-patch-gap-multiple-chinese-threat-actors-chain-0-day-exploits-in-chrome-windows/
- volexity.comVolexityhttps://www.volexity.com/blog/2026/09/21/mind-the-patch-gap-part-2-fake-websites-used-to-deploy-chrome-windows-0-day-exploits/
- zerodayinitiative.comZero Day Initiative (Trend Micro)https://www.zerodayinitiative.com/blog/2026/9/8/the-september-2026-security-update-review