Attack details
https://www.bleepingcomputer.com/news/security/massive-campaign-hits-elastix-voip-systems-with-500-000-unique-malware-samples/
Threat analysts have uncovered a large-scale campaign targeting Elastix VoIP telephony servers with more than 500,000 malware samples over a period of three months.
Elastix is a server software for unified communications (Internet Protocol Private Branch Exchange [IP PBX], email, instant messaging, faxing) that is used in the Digium phones module for FreePBX.