https://www.bleepingcomputer.com/news/security/elastix-voip-systems-hacked-in-massive-campaign-to-install-php-web-shells/

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.