Any file upload to EngagementHQ is restricted based on the file type to prevent upload of malware. The permitted file types are listed in this article on file types and sizes in EngagementHQ.
All files uploaded to EngagementHQ by clients or their participants are automatically virus-checked before storage. The virus checking is performed by an open-source product ClamAV. ClamAV® is an open source antivirus engine for detecting trojans, viruses, malware & other malicious threats.