Security researcher Nguyen Jang uploaded a proof-of-concept exploit (PoC) to GitHub in March for the Microsoft Exchange ProxyLogon vulnerability. GitHub said they took down the PoC to protect Microsoft Exchange servers that were being heavily exploited at the time using the vulnerability. However, GitHub faced immediate backlash from security researchers who felt that GitHub was policing the disclosure of legitimate security research simply because it was affecting a Microsoft product. In April, GitHub issued a ‘call for feedback’ to the cybersecurity community regarding their policies for malware and exploits hosted on GitHub.
Source: https://www.bleepingcomputer.com/news/security/githubs-new-policies-allow-removal-of-poc-exploits-used-in-attacks/