Hi!
If I compress my executable using --best all is fine.
If I use --ultra-brute to get a (significantly) better compression ratio the PrevX Anti Virus software will report the executable to be a High Risk Worm, as you can see here:
http://www.virustotal.com/analisis/eba82df299e93855b50aa36fd165b27beb5c52609a42b5daf3fe60c6789c958f-1245894393
The eSafe AV Software reports a...
2009-06-25 01:59:41 UTC in UPX - a powerful executable packer