Anti virus software does not use solely signatures anymore. They use heuristics analyses to detect viruses. What is the main thing a virus does? Exactly create executable files and for this a compiler and every program it generates is the base line of a virus.
For the uploaded file in virustotal: if less then half of the scanner are negative and the other half uses the same signature base (Gen:Variant.Symmi.86658) you can ignore this...
FYI:
http://wiki.c2.com/?TheKenThompsonHack(i have uninstalled all anti virus since 6 years and never had any problems, on contraire, they generate more problems and slowdowns.... Brain.exe, no script and adblock are my anti virus)