Could you clarify or what you expect it to contain (e.g., a driver, a game asset, or a data set)?
: You can use the 7-Zip File Manager or WinZip to "look inside" the archive without fully running any executable files it might contain.
: The prefix "GEN" often stands for "Generic" or "Generated." Combined with "100MB," it suggests this may be a dummy file or a benchmark file exactly 100 megabytes in size, frequently used for testing network speeds or disk performance.
: Use the SHA or CRC checksum feature in 7-Zip to ensure the file hasn't been corrupted during download.
: Before opening, upload the file to VirusTotal to check for malware signatures across dozens of antivirus engines.