I got a response from antivir that they could not find anything suspect in the zip file. In the latest update from antivir it no longer detects SPR/KeyLogger.EJ in wuu.exe so it seems that it was a false positive. Good news.
I haven't found any info on SPR/KeyLogger.EJ so this might be a false alarm from antivir though I think I will wait with using autoupdate in WUU or manual download of the beta until this is confirmed. I also changed my wow account password just in case ...
This does not happen with the 1.6.520 version and if you click no on autoupdate.
If anyone can clearify if this is a false positive it would be nice.
I sent the file to antivir and asked them to check if this is a false positive but I haven't received any response yet.