I would rather look for another program that can do the same task than use one detected as a trojan, but before we go down that road.

What is the program name ?
What was the infected file name, where was it found example (C:\windows\system32\infected-file-name.xxx) ?
What avast! version and VPS file (virus database) number, e.g. 0630-2 (see about avast!) ?
Have you confirmed that the detection is correct ?

You could also check the offending/suspect file at: VirusTotal - Multi engine on-line virus scanner
Or Jotti - Multi engine on-line virus scanner if any other scanners here detect them it is less likely to be a false positive. You can’t do this with the file in the chest, you will need to move it out.

It is possible to exclude(standard shield, advanced and program settings, exclusions) the executable file name but first I think you should seek confirmation above.