MAL-2026-12259 Malicious code in tinkoff-statist-browser-typed-client-eventea.projects.finhealthwebmicroblocks (npm)

On require() of this package, index.js loads _vendor.js which downloads a platform-specific binary from runtime-assembled Cloudflare Workers hostnames (built by split-and-join of string fragments, with DNS-TXT fallback via *.dl.well1.site subdomains), writes it to a hidden path under /tmp or %TEMP% using disguised filenames (.cache_<uid> on POSIX, dotnet_diag_<uid>.exe on Windows), sets mode 755 via fs.chmodSync, and spawns it detached with cp.spawn('/bin/sh', ['-c', path+' &'], {detached:true}).unref() or cmd.exe start /b. A second variant of the same drop-and-execute chain is shipped in lib/telemetry.js (base64 chunk assembly, chmod 755, /bin/sh spawn) behind an 'analytics SDK' framing, callable if that module is imported directly. Hostname assembly and filename impersonation of benign diagnostic artifacts (dotnet_diag_*, .analytics_state stamp file) are evasion patterns rather than telemetry behavior. Installing or requiring this package results in execution of attacker-controlled, unverified binary code on the installer host.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.