Hi,
Avast SecureLine VPN started to create a service user '_avastsecurelinekillswitch' since the last update. The Kill Switch functionality uses it for DNS queries during a VPN session establishment. Similarly to other service users in the system, the user is marked as hidden not to be visible in a login window. Could you please tell me what is your operating system version? The login window can behave differently on computer launch; after user logout; with fast user switching and even be replaced with some custom solution (i.e. Microsoft). Do you see the 'Other' user in all or only in some specific login situations?
Thank you very much for letting me know about the issue,
Martin