If you downloaded it from kinook.com, it definitely does not contain a virus, trojan, or other malware. Most likely, the anti-virus software is mistakenly reporting a false positive. It also tests clean on
http://www.virustotal.com/. Report the problem to the vendor of the anti-virus software.
You could also try downloading the regular installer, then copy the installed files to the portable drive (the portable ZIP and regular installer contain the same files).