The vulnerability linked to Sandworm activity, CVE-2019-10149, can allow for Remote Code Execution (RCE) on the vulnerable host depending on Exim’s configuration and if it is remotely accessible.
DomainTools cannot make a definitive determination, based on these details it appears that the intruder likely used a vulnerability such as CVE-2014-3828, a SQL injection vulnerability in Centreon patched in version 2.5.3, to write data to the vulnerable system (such as a webshell) which could facilitate