To be sure that your execute file which you download from internet is safe(without any infected hided). below are some of the online virus scan which i used to:
1- VirusTotal – Uses several antivirus products to scan files (Antivirus File Scanner)
2- Jotti – Uses several antivirus products to scan files. (Antivirus, Malware File Scanner)
just upload the file and wait a few minutes you will see the result of your execute file.
Cheer!!