Google Search Console is super useful and helpful and the messages can be critical for the performance and safety of your web site. But some messages are not as useful, such as the uncommon downloads notification.
Over the past few weeks, webmasters have been reporting getting a ton of these and were unsure how to act on them. The help document has this under the security issues report and says:
Your site is offering a download that Google Safe Browsing hasn't seen before. The Chrome browser may warn that it is uncommonly downloaded and could be dangerous. These warnings are lifted automatically if Google Safe Browsing verifies that the files are safe.1. Fix the problem
Find and confirm whether your downloads conform to the download guidelines. If any of the downloads violate these guidelines, remove them. If they do not violate these guidelines, you do not need to remove them, simply request a review, as described next. Note that example URLs are not always given for this issue.2. Request a review
When you're finished removing files (or verified that your downloads conform to the guidelines), request a security review in the Security Issues report. A review can take from a few days to a few weeks to complete.
But most people who get these do not know where to start when it comes to fixing the problem and want Google to be more specific about where to find the issue.
So John Mueller of Google said on Twitter that his advice is that if you can't find the issue on your web site then just submit a request for review and then ignore it. If Google comes back to you with another message with more details, then go ahead and fix it. Otherwise, don't worry about it.
Here is John's tweet:
I'd recommend just requesting review and ignoring it unless it comes back with malware. Uncommon downloads can be pretty common, we warn the site owner about them, but they won't cause problems otherwise on your site.
— 🍌 John 🍌 (@JohnMu) December 20, 2019
Forum discussion at Twitter.