Please rest assured that the W32/NGVCK.d virus McAfee AntiVirus software alerted you to is not actually present in Grey Goo. This is a false positive which we have worked with McAfee to correct. If you have not updated your virus signatures from the time this issue was resolved, the software will continue to alert you of this issue. To resolve the issue, simply update your signature files. If you are unsure how to do so, you can find help on the official McAfee website for further assistance.
Please let us know if we can be of further assistance. Thanks!