If you are running Symantec antivirus, and trying to install Flash, and the Installer is being flagged as a Trojan Horse, now you know why.  Seems there might be a false positive in Symantec's host based detection, flagging the Adobe Flash Installer as a Trojan Horse.

This isn't a big slight, this happens from time to time, with the thousands and thousands of different types of detection that is done with an antivirus tool, it's actually fairly impressive that this type of thing doesn't happen more often.  But it's happened before, and it will happen again.  (Remember the Excel file fiasco that McAfee's AV caused?)

Symantec is encouraging people that are affected to call Symantec support.  I am sure this will be resolved very soon.

Seems that the affected Revision is: 2010-01-27 rev 049.

I'll update this post when it's corrected.

UPDATE: This has been fixed: http://www.symantec.com/connect/forums/flash-player-false-positive#comment-3520451

-- Joel Esler | http://blog.joelesler.net | http://twitter.com/joelesler