using a reputable tool like VirusTotal to check for hidden malicious code.
There is a chess player named Stefan Krstic . In chess communities, ".zip" files are frequently used to share game archives (PGN files) or player-specific databases. Krstic_Stefan.zip
The name appears to be a personal file, likely belonging to one of several professionals named (a common name in Serbia and surrounding regions). Based on common uses for such file naming conventions, it is most likely one of the following: using a reputable tool like VirusTotal to check