I have CIS 5.10.
Manual scanning is established - 200 Mb.
Scans normally. In .exe-There 2 files.
If you want to scan.
Create the folder. For example with the name OpenOffice.
Unpack OpenOffice at installation. (Postpone installation).
Then it is possible to scan if it disturbs you.
Edit: There everything is normal. Simply there is no digital signature.