I guess that if a DDG hijacker actually exists (which I have seen no evidence of) you would have to ask the persons responsible for creating\distributing the program what the purpose of the hijacker is.

From what I see, the 2 sites that you supplied are the culprits, not of spreading the hijacker, but of falsely misrepresenting DDG and it's search tools. The information provided in both pages is false and I certainly wouldn't download anything or take any advice from either of these sites.
posted by x.15a2 Community Leader2 years and 4 months ago Link

Well, someone came to Duckco, and said the following: "Hello, what is DuckDuckGo, it randomly came on my computer one day, and I'd like to use Google. That might be evidence, but it also supports being culprits.
posted by OpalYeah7800 2 years and 3 months ago Link
Over time some browsers (Safari, Pale Moon, Firefox, etc.) have added DDG to their list of search engines (some have even pushed it to be the default search) and some users aren't familiar with it and conclude that their browser's search has been hijacked. This may or may not have been the case in this instance.
posted by x.15a2 Community Leader2 years and 3 months ago Link