I have here an internal brochure produced by my company. Here's a quote "...to eliminate the disbenefits of noise...
This is not the first time I've seen the word "disbenefit" used in the corporate communications to refer to negative consequences.
The first time I saw the word, I really hated it. I still don't like it. I hated it because I thought it wasn't in the dictionary. I still dislike it because it's not a necessary coinage, and it sounds like another management buzzword. The opposite of a benefit can already be a detriment, a drawback, a disadvantage, a loss.
The arguments in favour of this word being recognised is that language is not static, even if the new word is created by a management consultant; and simply that we understand what it means. if the prefix dis- can be coupled with words like advantage, agreement, enchantment, repute, incentive and location, why not with benefit?
Actually, this word is not completely unknown to all dictionaries. "disbenefit" is in the big Oxford English dictionary, but not the concise one.
Google returns 4470 pages containing "disbenefit". Allwords.com defines it using the same antonyms for benefit that I used above, and suggests that it dates back to the 1960s. However this google page count of 4470 is miniscule compared to the 29 million pages that contain the word "benefit", 1.9 million containing "disadavantage" and 1.1 million containing the word "drawback".
I suggest that you avoid using this coinage. Many people will never have heard it before. You might confuse people who don't understand it, and annoy pedants who do. There exist other good words that have the same meaning. "disbenefit" has not been in common enough use to acquire much connotation different from the alternative words, so there really is no difference.