China-Aligned TA415 Exploits Google Sheets & Calendar for Covert C2 in U.S.-China Espionage Campaign

China-aligned TA415 (APT41) uses Google Sheets and Calendar for covert C2 in espionage targeting U.S. entities on U.S.-China policy. July-August 2025 spearphishing spoofed officials, linking to archives on Zoho/Dropbox/OpenDrive via Cloudflare WARP. Targets triggered malicious LNK in MACOS folder, running logon.bat for WhirlCoil loader and PDF decoy.


WhirlCoil deploys scheduled tasks (e.g., GoogleUpdate), downloads legit VS Code CLI, and creates Remote Tunnel via GitHub for shell access/exfil without beaconing. C2 embeds instructions in Sheets (payload markers) and Calendar (base64 events); metadata POSTed to logging services under encoded filenames.


Evolving from Voldemort, TA415 (tied to China's MSS/Chengdu 404) steals trade/sanctions intel amid tensions. Evades defenses via trusted cloud tools; counter with cloud anomaly detection, behavior analytics, and monitoring unusual Sheets/Calendar activity.
NPAV offers a robust solution to combat cyber fraud. Protect yourself with our top-tier security product, Z Plus Security