ESET HQ has confirmed that scanning is active and functioning across Email, Teams, OneDrive, and SharePoint.
To validate this, they recommend using the EICAR test file, a standardized, non-malicious file used by all major antivirus vendors to ensure that antivirus scanning is working correctly. You can safely download it from the official site:
In addition to the EICAR test, ESET HQ also provided a phishing test link, which will be detected as phishing by ECOS. This helps verify phishing protection:
http://paranoia.cz/testlink/phishing
Please let me know if you need any assistance with testing or interpreting the results.