VERY IMPORTANT

A Chinese-speaking threat actor conducted a large-scale SEO poisoning campaign dubbed 'Operation Rewrite' using BadIIS malware to manipulate search results. The attackers compromised legitimate websites and used malicious IIS modules to intercept web traffic and serve altered content. The campaign targeted East and Southeast Asia, particularly Vietnam. Multiple variants of BadIIS were discovered, including ASP.NET handlers and PHP scripts. The threat actor is linked to previously known groups like Group 9 and possibly DragonRank. Their toolkit allowed them to inject malicious content, redirect users, and exploit compromised servers for various malicious purposes.