tinkoff-fb-service-prefill-profile-contact@20.2.3

Analysis

A trojanized package impersonating a Tinkoff internal SDK. On require(), it downloads a second-stage binary from attacker-controlled Cloudflare Workers endpoints (oob-worker[.]cf101-adf[.]workers[.]dev, oob-worker[.]cf99-9b3[.]workers[.]dev, oob-worker[.]cf103-070[.]workers[.]dev, oob-worker[.]cf102-baf[.]workers[.]dev) at path /pkg/package (or platform-specific variants /pkg/package-arm64, /pkg/loader_mac, /pkg/package.exe). If HTTPS download fails, it falls back to a DNS TXT exfiltration channel via c[.]tin[.]dl[.]well1[.]site (and platform-specific variants tina[.]dl[.]well1[.]site, ldr[.]dl[.]well1[.]site, win[.]dl[.]well1[.]site) to retrieve a base64-encoded payload. The downloaded binary is written to /var/tmp/.cache_<random_hex> (or C:\Windows\Temp\dotnet_diag_<random_hex>.exe on Windows) and executed as a detached background process. The package also probes for sandbox environments via a DNS TXT query to _leitwacht.attached.local.