Hackers Chain Chrome and Windows Zero-Days in New BlueMoon Exploit Kit Attacks
Multiple espionage actors, mostly China-nexus, are chaining Chrome V8 and Windows kernel zero-days (CVE-2026-85046, CVE-2026-85880) via the BlueMoon exploit kit against government and defense targets.
Proofpoint identified a new exploit kit dubbed BlueMoon chaining a Chromium V8 type-confusion RCE (CVE-2026-85046), a V8 sandbox escape, and a Windows kernel LPE (CVE-2026-85880). At least four distinct threat clusters, most with suspected China nexus, adopted the kit within days starting with TA412 (Violet Typhoon/APT31) on August 28, 2026. Both Chrome-side flaws were patch-gap zero-days with roughly a four-week exploitation window; the Windows LPE only works on Windows 10 and Server 2019/2022. TA412 used spearphishing posing as university interns to deliver the GemStone browser backdoor disguised as a Google Gemini extension; other clusters delivered ShadowPad via DLL sideloading and a Rust loader against targets in aerospace, government, and finance.
Four Nation-State Actors Used the Same Chrome Zero-Day Exploit Kit Within 12 Days
Proofpoint reports four nation-state actors, mostly China-nexus, adopted the BlueMoon Chrome and Windows zero-day exploit kit within 12 days, targeting US organizations.
Proofpoint tracked an exploit kit dubbed BlueMoon that chains CVE-2026-85046, a Chrome V8 type-confusion bug, with an unnamed V8 sandbox escape and CVE-2026-85880, a Windows kernel privilege escalation using ALPC and the Windows Notification Facility. The first observed use was by China-nexus TA412 (APT31, Violet Typhoon, JungleBamboo) on August 28, 2026 against US NGOs, mining companies, and commodity trading firms, followed by UNK_LateNight targeting US aerospace and defense companies on September 2. Both V8 bugs were patch-gap zero-days: the fix was committed to Chromium on August 7 but reached stable Chrome on September 3, enabling rapid weaponization from public patches. TA412's post-exploitation payload, GemStone, is a malicious browser extension posing as an AI-powered Google Gemini companion that captures keystrokes, cookies, screenshots, and browsing history via a Cloudflare Worker C2.
Breeze Comet Executes Hundreds of Fraudulent Transactions via Brazilian Payment Systems
Google/Mandiant profile Breeze Comet, a Brazil-based e-crime group executing fraudulent Pix and STR payment transactions at banks, retailers, and fintechs.
Google Threat Intelligence Group and Mandiant describe Breeze Comet (formerly UNC5669), a financially motivated threat actor active since September 2023 targeting Brazilian financial services, retail, and e-commerce. The group gains access via password spraying, vishing impersonating IT support to install RMM tools like AnyDesk, WhatsApp social engineering, and exploitation of vulnerable JBoss AS servers for web shell deployment. It uses compromised government websites as C2, deploys the Rust-based COBALTSPIN tunneler and multiple custom backdoors (LIGHTPAINT, MILDFROST, KICKPLATE, BOATBEAM), then clears logs after executing hundreds of fraudulent transactions through Pix, STR, and Boleto payment systems. At least one heist yielded tens of thousands of dollars, with infrastructure suggesting expansion toward Latin America and Africa.
Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
Risky Bulletin: The EU publishes its upcoming cybersecurity standards
ETSI releases 17 draft cybersecurity standards vendors must meet when the EU Cyber Resilience Act takes effect in December 2027.
The European Telecommunications Standards Institute published 17 interim draft standards covering operating systems, routers, firewalls, VPNs, SIEMs, browsers, password managers, smart home devices, toys and wearables. They mandate basic security features such as post-sale updates, shipped SBOMs, modern cryptography and secure-by-default settings; public comments run until November, with final versions expected in December, one year before CRA compliance begins in December 2027. The newsletter also reports Irregular taking responsibility for AI test-environment escapes involving Anthropic and Meta frontier models, a breach at France's tax agency exposing 678,000+ citizens' data claimed by hacker ZeroBytes, and Kazakhstan eGov data covering 15 million citizens listed for sale on an underground forum. Additional briefs cover a $3.2 million Harmony Protocol theft crashing the ONE token 40%, Columbus Police still restoring systems two years after ransomware, DDoS attacks on Threema's provider, and Ukraine's GUR claiming a cyberattack on Wildberries.
Security Affairs newsletter Round 590 by Pierluigi Paganini
Weekly Security Affairs newsletter roundup aggregating top cybercrime, malware, APT and AI security stories including ExfilSquad, Kimwolf v7 and Kimsuky AI use.
This is the Round 590 weekly newsletter from Security Affairs, linking to the week's major stories rather than reporting a single incident. Headlines include ExfilSquad extortion, a 7.3M chess.com record leak, Kimwolf botnet v7, SharePoint exploitation after a public PoC, Kimsuky integrating AI, and China-linked autonomous-style attacks. It is a digest and promotional item with no standalone technical details.
Three Threat Groups Target Russian Enterprises With Backdoors, Ransomware, and Wipers
Kaspersky details NightEagle, Hacking Cat, and Toy Ghouls targeting Russian enterprises with Exchange backdoors, Gorilla RAT, and destructive Monkey ransomware.
Kaspersky reports three threat clusters targeting Russian enterprises: NightEagle (APT-Q-95), the pro-Ukrainian hacktivist group Hacking Cat, and Toy Ghouls. NightEagle uses compromised VPN credentials and the GhostContainer modular backdoor to fully compromise Microsoft Exchange servers, chaining CVE-2020-0688 exploitation, BlueKeep (CVE-2019-0708), Active Directory vulnerabilities, and DCSync to seize domain controllers. Hacking Cat exploits Exchange flaws including CVE-2021-26855 and CVE-2026-42897 to deliver the Gorilla RAT and multiple Monkey ransomware variants written in Rust, .NET, C++, and Golang targeting Windows, Linux, and VMware ESXi, with some variants acting as wipers that never store the encryption key.
Risky Bulletin: Russia starts blocking DoH and DoT
Russian users report blocks on DoH and DoT servers, including Cloudflare 1.1.1.1 and Google 8.8.8.8, in an apparent censorship crackdown.
Russian internet users began reporting failures connecting to DNS-over-HTTPS and DNS-over-TLS servers, suggesting a government crackdown on the two privacy protocols. The blocks reportedly cover Cloudflare's 1.1.1.1 and Google's 8.8.8.8 resolvers; Roskomnadzor has not officially confirmed the action. The agency tested a similar block in March on Beeline's network and had named DoH for blocking as early as 2021. The bulletin also briefly notes state-sponsored phishing of EU officials, a DDoS against Norway's Digdir, the ReliaQuest/ShinyHunters dispute, and older ransomware and breach disclosures.
TWINLOOT Abuses SharePoint and Teams to Steal Credentials and Move Across Networks
Ontinue disclosed TWINLOOT, a Python implant hiding C2 in SharePoint dead drops and Teams TURN relays, harvesting credentials and pivoting via reverse SOCKS5.
Ontinue's Cyber Defense Center identified TWINLOOT during a July 2026 campaign investigation: a modular, PyArmor-hardened Python implant (a 39 MB bootstrap-fat.pyc loader) whose entire C2 infrastructure lives inside trusted Microsoft services. Tasking flows through SharePoint Online file dead drops polled every 15 seconds via the Microsoft Graph API, while interactive operator access uses WebRTC DataChannels relayed by Microsoft Teams TURN servers; Graph traffic is driven by the victim's own headless Edge browser. The implant harvests Windows credentials with fake lock screens, offers a reverse SOCKS5 pivot for lateral movement to SMB, RDP, WinRM, and MSSQL, executes commands, and persists on hosts. Initial access is assessed to be Teams social engineering masquerading as IT support, prompting a PowerShell command to download the payload.