Update . . . after doing some research, I've found that Themida is legitimate software that is used to protect files from being "reverse engineered" by hackers. In this case, it is probably part of the Flight1 wrapper's anti-piracy protections.
This is a well-known and documented "False Positive," meaning that while your AV is detecting a Themida signature, it has no way to distinguish between a legitimate and illegitimate package.
Flight1 has been asking AV folks for YEARS to update their signature files to stop this false reporting to absolutely no avail. See post #14 in this thread from Steve Halpern directed to the folks at ESET (makers of NOD32), dated September 13, 2007:
http://www.wilderssecurity.com/showthread.php?t=184840
See also this thread at AVSIM from 2009. What it comes down to in the end is whether you trust the source of the software you're trying to install. Flight1 has been in business more than long enough to have earned our trust.
