If this was part of a specific download from a website, try to see if it completes with a proper name and extension.
: Always run the file through an online scanner like VirusTotal before attempting to open it.
Could you tell me or what you were trying to download when it appeared?
: You can use a hex editor like HxD to look at the first few bytes (the "magic numbers") and match them against a File Signature List to see what it actually is.
If this was part of a specific download from a website, try to see if it completes with a proper name and extension.
: Always run the file through an online scanner like VirusTotal before attempting to open it.
Could you tell me or what you were trying to download when it appeared?
: You can use a hex editor like HxD to look at the first few bytes (the "magic numbers") and match them against a File Signature List to see what it actually is.