No. HDoujin Downloader is clean and always will be.
Every once in a while, when a new program update is released, some antivirus programs will flag it as potentially malicious. This is normal, and the new version is eventually whitelisted within a few days.
Why does this happen?
Antivirus programs use heuristic engines to discover new malware. This means they use a set of characteristics to determine if something is likely to be malicious or not. When the scanner comes across a new version of HDoujin Downloader, it thinks “What is this? I haven’t seen this before! Oooh, it can download files? Seems suspicious, I’m flagging this!”.
This is where whitelisting comes in. The people who run the antivirus software will add it to a list of programs that says “Hey, we looked at this one and it’s actually fine, ignore it”. When a new release makes significant enough changes, it’s not recognized as the same program anymore, and thus appears to be no longer whitelisted. When this happens, it needs to be resubmitted for whitelisting.
What can I do?
If you’re having a hard time running a new version of HDoujin Downloader (e.g., your antivirus software keeps deleting it), you can add the program’s folder to your exclusions list. You can instructions explaining how to do this for Windows Defender here, but if you use a different antivirus software you will need to look up instructions specific to that program. When you’re unsure of what to do, feel free to ask.
You can also tell me that the program is being flagged so I can submit a false-positive report if you think I’m not already aware of it. Most antivirus vendors also offer a means for customers to submit false-positive reports themselves as well.