One Click on a Malicious Link Lets Hackers Backdoor Sogou Input Method Users
Actively exploited one-click flaw in Sogou Input Method (CVE-2026-51990) let UNC3569 deploy the GRAYRABBIT espionage backdoor on Windows.
Gen Digital researchers found three weaknesses in Sogou Input Method's sgbiz protocol handler that chain into a one-click RCE running with the signed-in user's permissions. UNC3569 used the chain in an active intrusion, leveraging an unsandboxed Chromium 80 embedded browser, the known V8 flaw CVE-2021-38003, and DLL sideloading via 7-Zip to deploy the GRAYRABBIT backdoor. Tencent fixed the issue in version 16.3.0.3498 within 12 days of disclosure; Sogou is used by hundreds of millions of people, mainly in China.
BlueMoon exploit kit turns Chrome and Windows flaws into attacks
Proofpoint documents BlueMoon exploit kit used by four espionage groups to chain Chrome V8 and Windows flaws via phishing, all now in CISA's KEV.
Proofpoint identified a shared Chrome and Windows exploit kit, BlueMoon, used by four espionage groups against Chrome on Windows within days of one another. Attacks began with phishing emails leading to web pages that exploited two Chrome V8 vulnerabilities, followed by a Windows flaw to escape browser protections and gain higher privileges. The Chrome flaws were patched in Stable on September 3 and 8, 2026, the Windows flaw was fixed in September Patch Tuesday, and all three were actively exploited and added to CISA's KEV catalog. Researchers found clues, but no conclusive evidence, that the kit was developed with AI assistance.
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.