Some tips to improve the security of your servers: First of all, to improve security, you need to change all Windows account passwords without exception. You need to change them to long and complex passwords. Secondly, you need to install antivirus software on all servers without exception (Kaspersky, Sophos, Bitdefender or other reliable antivirus software). You also need to more carefully monitor activity on the corporate network, look for unnecessary activity on the network (track traffic) and not run third-party software on machines without antivirus software.