Today, during a pentest, I encountered the following error when running the Psexec Metasploit module with local account credentials

• Exploit failed: ActiveRecord::RecordInvalid Validation failed: Value can’t be blank

I was a little thrown off by this as I have never experienced it before. It is a Ruby error referring to an empty smbdomain field. Although the field is still optional, you must enter a period, “.”, in order to get Psexec modules to execute. I have not tested other modules so this may be isolated to only a few.