Stupig

Symantec identified renewed activity of Backdoor.Daxin, a sophisticated China-linked kernel-mode rootkit that hijacks legitimate TCP connections for covert C2, on a Taiwan manufacturing subsidiary in May 2026, four years after its initial public disclosure. Alongside it, researchers discovered a new backdoor, Stupig, which abuses the Windows keyboard-layout provider mechanism to execute SYSTEM-level commands from the logon screen pre-authentication and hook credential-handling APIs within winlogon.exe. Compile timestamps on both tools date to 2013 despite the host having no telemetry until 2026, suggesting a potentially decade-plus dwell time enabled by likely initial access via an outdated, end-of-life Digiwin SSO/JDK deployment.