You need software that can "re-stitch" these files together. : The industry standard for .rar files.
The archive is encrypted. Fix: You must obtain the password from the source who shared the files. There is no legitimate "backdoor" for RAR passwords. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.part1.rar
Because RAR archives contain other files, they are a common vector for malware. Follow these rules: You need software that can "re-stitch" these files together