"Modified Malt" is probably a way of describing maltitol which is made by chemically altering maltose - a sugar from malted grains. Maltitol is definitely a polyol or sugar alcohol.

There's tons of posts and articles, too (see the "truth about low carb sweeteners info" quick link over on the right?) about sugar alcohols here.

Always best to ask the makers to clarify if that's maltitol, is there a webpage or contact information on that package?