Spearphishing via remote template to force authentication

A spearphishing lure that references a remote resource can cause a Windows client to authenticate to an untrusted server. Supported examples include a remote Office template that prompts a user for credentials and remote SMB/WebDAV resources referenced by a lure file; the exact result depends on the client, trust-zone and network policy. The material may be credentials explicitly entered into a prompt or an NTLM challenge-response, not automatically plaintext credentials. A generic HTTP-hosted image request alone does not establish that authentication material was sent.