If the contents are legitimate scientific data, use these tools: To visualize 3D structural coordinates. BLAST: To compare the sequence against known databases.
If this file is from a research or academic setting, it typically contains: CBP21prot rar
To extract the files (ensure your antivirus is active). If the contents are legitimate scientific data, use
FASTA files containing the amino acid sequence of the protein. CBP21prot rar
Use VirusTotal to check the archive before opening.