MAL-2026-12231 Malicious code in tinkoff-boxy-form-desktop-sme-registration-ooo (npm)

Package name typosquats Tinkoff's official SME registration form. On require() of the package, index.js loads ext.js, which reconstructs attacker-controlled hostnames from string fragments (e.g. 'oob-worker.cf101-adf.workers.dev' and 'tin.dl.well1.site'), fetches a platform-specific binary over HTTPS, and falls back to reconstructing the payload from base64 chunks served in DNS TXT records under *.dl.well1.site when HTTPS is unavailable. The fetched bytes are written to /tmp or %TEMP% under disguised filenames (dotnet_diag<rand>.exe,.cache_<rand>, loader_mac), marked executable with chmod 0755 on Unix, and spawned detached via cp.spawn('/bin/sh', ['-c', fp + ' &']) on Unix or cp.spawn('cmd.exe', ['/c', 'start', '/b', fp]) on Windows. The dropper is unrelated to the package's advertised purpose as a form/SDK.

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.