The Hoaxcalls botnet is built to carry out large-scale distributed denial-of-service (DDoS) attacks. One of its hallmarks is that it uses different vulnerability exploits for initial compromise. The DDoS group sets itself apart by using exploits but it doesn t always pan out. To date, the group has incorporated 12 different exploits since March, according to Radware researcher Daniel Smith. Some of the exploits that the group tried but abandoned include the bugs tracked as CVE-2018-10562 and CVE-2019-10561.
Source: https://threatpost.com/inside-hoaxcalls-botnet-success-failure/156107/