Calibre portable 3.1 detected as virus

Hello.

I'm trying to run calibre portable 3.1 on windows 7. Symantec antivirus detects calibre.exe as a risk type Suspicious.Cloud.5.A and prevents execution.

This does not happen with calibre portable 3.0.

Since this is at work I cannot change any antivirus configuration.

Is there any solution?

I hope this will help to get it working.