Chinese espionage groups swarm to exploit triple-link chain of zero-days
At least four China-aligned espionage groups chained three zero-days in Chromium browsers and Windows ALPC for espionage since late August.
Proofpoint observed at least four state-aligned threat groups, starting with TA412/Violet Typhoon/APT31 on August 28, chaining three zero-days in the 'BlueMoon' exploit chain targeting Chrome, Chromium-based browsers and Microsoft Windows. The chain includes RCE flaws in Chromium's JavaScript engine (CVE-2026-85046, CVE-2026-87491) and a Windows Advanced Local Procedure Call privilege-escalation zero-day (CVE-2026-85880), enabling sandbox code execution, sandbox escape and system privileges. APT31 delivered the chain via phishing links to NGOs, mining and commodity trading firms in the US, installing a browser extension disguised as Google Gemini to surveil activity and steal credentials. Other groups (UNK_LateNight, UNK_DoubleCheck, UNK_QuietRacket) targeted US aerospace, Vietnamese manufacturing, and Indonesian and Singaporean organizations; fewer than 20 victims were directly observed but the true count is likely higher.
Multiple Chinese hacking groups seen using identical Chrome zero-day exploit
Four China-linked espionage groups share identical BlueMoon Chrome zero-day exploit kit targeting US defense contractors and Asian government agencies.
Proofpoint identified at least four Chinese-aligned espionage groups (TA412/RedBravo, UNK_LateNight, UNK_DoubleCheck, UNK_QuietRacket) using an identical Chrome zero-day exploit kit dubbed BlueMoon in late August through this week. Targets include US defense contractors, NGOs, mining companies, and Southeast Asian government agencies. The exploit chains a Chromium patch-gap vulnerability with a Windows flaw, delivering malware such as ShadowPad and a fake Gemini browser extension backdoor, with possible AI-assisted exploit development.
BlueMoon Exploit Kit Chains Recent Chrome, Windows Zero-Days
Proofpoint reports multiple espionage groups rapidly adopting BlueMoon, a new exploit kit chaining Chrome and Windows zero-days.
Proofpoint identified a new exploit kit, BlueMoon, chaining two Chrome V8 zero-days (CVE-2026-85046, CVE-2026-87491) with a Windows ALPC privilege escalation zero-day (CVE-2026-85880), all patched between September 3 and September 2026 Patch Tuesday. China-linked Violet Typhoon (APT31) first used it on August 28 against US NGOs and mining/commodity trading firms; UNK_LateNight, UNK_DoubleCheck, and UNK_QuietRacket adopted it within days against targets in the US, Vietnam, Indonesia, and Singapore. The kit exploits the V8 defects for sandbox escape, fingerprints the host, and injects a CreateProcess stub into the Chrome broker process to download and execute a payload via curl. Development artifacts suggest the kit's creators may have used AI to build it, potentially lowering the barrier to exploit development.
4 groups caught using the same Chrome and Windows exploit kit
Proofpoint says at least four groups, some China-linked, actively share the BlueMoon kit chaining two Chromium and one Windows kernel exploit.
Proofpoint researchers report that at least four hacking groups, some with ties to the Chinese government, are actively using a nearly identical exploit kit named BlueMoon. The kit chains two Chromium browser vulnerabilities and one Windows kernel flaw affecting Windows 10, Windows 11 initial release, and a later Windows version to install malware of the attacker's choice. All three vulnerabilities received patches within the past 24 hours. Proofpoint attributes the kit's rapid, widely shared deployment to a Chromium patch-gap window and AI agents accelerating exploit development against publicly accessible upstream patches.
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.