Based on a search of public records, databases, and general internet searches, there is no widely known or officially documented academic paper, dataset, or legitimate file explicitly titled [1, 2].
Scan any such file with trusted antivirus software before attempting to extract it.
If this refers to a specific, obscure research paper, providing more context (such as the authors or topic) could help identify it. If you can provide more context, I can try to help further:
Often, files with technical extensions like .7z (a 7-Zip compressed archive) that are named in this format ("something5.7z") and lack public documentation may be associated with: