000a001.7z -
Naming schemes like this are common in forensic images of old server partitions or recovered RAID arrays.
Use 7-Zip (Windows) or Keka (macOS). On Linux, use the command 7za x 000a001.7z . 000a001.7z
Since these files are often part of a larger set, you can verify the file using a checksum (MD5 or SHA-1) if a manifest file is provided by the source. Naming schemes like this are common in forensic