Reference:
https://github.com/InQuest/awesome-yara
https://github.com/InQuest/yara-rules
https://github.com/Yara-Rules/rules
https://github.com/Neo23x0/signature-base/tree/master/yara
https://github.com/codewatchorg/Burp-Yara-Rules
https://github.com/tjnel/yara_repo
https://github.com/mikesxrs/Open-Source-YARA-rules
Not complete:
https://blog.nviso.be/2017/10/11/detecting-dde-in-ms-office-documents/