T1187
Forced Authentication
Windows1 piece on this siteT1187 on attack.mitre.org
Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept. The Server Message Block (SMB) protocol is commonly used in Windows networks for authentication and communication between systems for access to resources and file sharing.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Cloud account compromise
Impossible travel, an unrecognised inbox rule, or a reported invoice-fraud attempt.
Detect it
Hunts and rules you can run, each stating what it needs and what else it returns.
Sigma network pack: four rules for DNS, proxy and firewall logs
Long DNS labels, scripting-engine user agents at the proxy, executables fetched from a bare IP address, and SMB leaving the network. Written for the log sources most estates already collect and rarely alert on.
how MITRE says to see it
Detect Forced SMB/WebDAV Authentication via lure files and outbound NTLM
- Adversary stages a lure that references a remote resource (e.g., LNK/SCF/Office template). When the user opens/renders the file or a shell enumerates icons, the host automatically attempts SMB or WebDAV authentication to the attacker host.
what reduces it
- M1037 Filter Network Traffic. Block SMB traffic from exiting an enterprise network with egress filtering or by blocking TCP ports 139, 445 and UDP port 137. Filter or block WebDAV protocol traffic from exiting the network. If access to external resources over SMB and WebDAV is necessary, then traffic should be tightly limited with allowlisting.
- M1027 Password Policies. Use strong passwords to increase the difficulty of credential hashes from being cracked if they are obtained.