Select it and use the menu to either close Windows or repair the issue.
Are you referring to the antivirus program? Defender is the best free antivirus program, so it’s not recommended unless you have a premium subscription for a third-party program. Alternatively, how about the warning 
status in the Taskbar settings icon (open Defender, check what’s being recommended, dismiss if it’s something optional like OneDrive backups or take care if it’s something serious like pending scans, updates, or detected threats)?
Not the emblem, but the warning that is displayed on it, dude
or the warning status displayed on the icon; in this case, launch Defender, evaluate what’s suggested, disregard anything optional, like OneDrive backups, or proceed with caution if it pertains to something severe, like pending scans, updates, or threats discovered.
Additionally, look through “History” in case the warning indication originated from a PUA or something else. If not, use Storage Sensor to remove temporary files, then restart Windows.
When Defender opens, you can choose to ignore it or follow its instructions.
It’s mostly certainly only going to advise you to install OneDrive since Microsoft views it as a security precaution (against ransomware threats). Simply double-click it to reject the OneDrive warning that appears, and it will vanish permanently.
Alternatively, it may have discovered dangers; in that case, you should follow its instructions.
By the way, how is it a security feature? Wouldn’t One Drive data also be impacted if a malware encrypted every file separately? I apologize if this seems simple; I haven’t used Microsoft products regularly in years.
Yes, even though OneDrive offers file recovery and history.
OneDrive files are stored in the cloud, not on your PC. so when your data are encrypted, it does not affect them. I don’t need OneDrive, even though I still never use it.
Although I strongly advise against doing so unless you have third-party antivirus software, you can shut it down. It may be completely prevented from starting, I believe, by utilizing task management.
Or simply click on it to solve the issue. It can be as easy as verifying your account by typing your password once more.
Additionally, you can disable notifications and hide it from view on the taskbar.
No, I do not want the emblem to be removed; nonetheless, the warning 
on it