The below article would help you in recovering a file that is quarantined by virus scan .
http://service.mcafee.com/faqdocument.aspx?id=TS100617&lang=en_US&prior_tid=2&An swerID=16777218&turl==http%3A%2F%2Fkb.mcafee.com%2Finfocenter%2Findex%3Fpage%3Dc ontent%26id%3DTS100617%26actp%3Dsearch
In order to stop detection you would have to temporarily disable VirusScan for as long as it takes to report it to the Threat Center who may send you an extra.dat to stop its detection in the future.
See this discussion regarding how to do that: http://community.mcafee.com/message/6645#6645
That said, it's extremely unlikely that a keylogger would ever be cleared because of its nature, but one can hope.