Issue a "SHOW VERSION" command to LISTSERV.  The response should  include a line like the following:

For Windows:

Virus database version:      2018-02-06 08:52:37 (F-Secure Anti-Virus 9.52)

For Linux:

Virus database version:      2017-03-23_12 (F-Secure Anti-Virus 11.10)

Under Windows, the version number shown may cause confusion.  The version number "9.52" is correct; F-Secure Server Security 12.x (in this case, 12.12) reports the version of F-Secure Anti-Virus that is packaged into the Server Security suite.  You can confirm that you are running Server Security 12.x by right-clicking the F-Secure shield icon in the system tray and choosing "About . . . ", which shows among other things

F-Secure Server Security 12.12 build 104
F-Secure Anti-Virus 9.52 build 240