https://www.bleepingcomputer.com/news/security/attackers-are-scanning-for-vulnerable-citrix-servers-secure-now/

Security researchers have observed ongoing scans for Citrix Application Delivery Controller (NetScaler ADC) and Citrix Gateway (NetScaler Gateway) servers vulnerable to attacks exploiting CVE-2019-19781 during the last week.

This vulnerability impacts multiple Citrix products and it could potentially expose the networks of over 80,000 firms to hacking attacks according to a Positive Technologies report from December.