Q: My browser launches by itself and http://tundra.site opens with message “Thank you for downloading”. What does it mean?
A: To be short it means that your computer is likely to be infected with malware and potentially unwanted programs. The website http://tundra.site is know to open after the installation of PUP is completed. You need to cure your PC from malware as soon as possible.
Tundra.site: how to remove malware
1. Scan your PC using AdwCleaner. Then press Clean to remove all found adware and PUPs (full guide):
2. Install MalwareBytes Anti-Malware and perform a full scan (full guide). After the scan is finished agree to remove all found items and reboot your PC if necessary:
3. Remove temporary files, browser cache and cookies using CCleaner:
4. Check browser shortcuts and fix them if needed (full how-to):