T1187 Forced Authentication

Technique

T1187

Tactics

Credential Access

Research, 90 days

2

KEV CVEs mapped

0

SigmaHQ rules

8

Elastic, Splunk

16

thrunt rules

0

Upstream

https://attack.mitre.org/techniques/T1187

MITRE description

Adversaries may gather credential material by invoking or forcing a user to automatically provide authentication information through a mechanism in which they can intercept that information. 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. When a Windows system attempts to connect to an SMB resource it will automatically attempt to authenticate and send credential information for the current user to the remote system.(Citation: Wikipedia Server Message Block) This behavior is typical in enterprise environments so that users do not need to enter credentials to access network resources. Web Distributed Authoring and Versioning (WebDAV) is also typically used by Windows systems as a backup protocol when SMB is blocked or fails. WebDAV is an extension of HTTP and will typically operate over TCP ports 80 and 443.(Citation: Didier Stevens WebDAV Traffic)(Citation: Microsoft Managing WebDAV Security) Adversaries may take advantage of this behavior to gain access to user account hashes through forced SMB/WebDAV authentication. An adversary can send an attachment to a user through spearphishing that contains a resource link to an external server controlled by the adversary (i.e. [Template Injection](https://attack.mitre.org/techniques/T1221)), or place a specially crafted file on navigation path for privileged accounts (e.g. .SCF file placed on desktop) or on a publicly accessible share to be accessed by victim(s). When the user's system accesses the untrusted resource, it will attempt authentication and send information, including the user's hashed credentials, over SMB to the adversary-controlled server.(Citation: GitHub Hashjacking) With access to the credential hash, an adversary can perform off-line [Brute Force](https://attack.mitre.org/techniques/T1110) cracking to gain access to plaintext credentials.(Citation: Cylance Redirect to SMB) There are several different ways this can occur.(Citation: Osanda Stealing NetNTLM Hashes) Some specifics from in-the-wild use include: * A spearphishing attachment containing a document with a resource that is automatically loaded when the document is opened (i.e. [Template Injection](https://attack.mitre.org/techniques/T1221)). The document can include, for example, a request similar to <code>file[:]//[remote address]/Normal.dotm</code> to trigger the SMB request.(Citation: US-CERT APT Energy Oct 2017) * A modified .LNK or .SCF file with the icon filename pointing to an external reference such as <code>\\[remote address]\pic.png</code> that will force the system to load the resource when the icon is rendered to repeatedly gather credentials.(Citation: US-CERT APT Energy Oct 2017) Alternatively, by leveraging the <code>EfsRpcOpenFileRaw</code> function, an adversary can send SMB requests to a remote system's MS-EFSRPC interface and force the victim computer to initiate an authentication procedure and share its authentication details. The Encrypting File System Remote Protocol (EFSRPC) is a protocol used in Windows networks for maintenance and management operations on encrypted data that is stored remotely to be accessed over a network. Utilization of <code>EfsRpcOpenFileRaw</code> function in EFSRPC is used to open an encrypted object on the server for backup or restore. Adversaries can collect this data and abuse it as part of an NTLM relay attack to gain access to remote systems on the same internal network.(Citation: Rapid7)(Citation: GitHub)

Research citing this technique

Reports and advisories from the last 90 days that cite this technique.

• 2026-10-21 Group-IB: Stray Cat, Open Doors: How k0t Wanders Through the Network Edge
• 2026-10-15 Google Threat Intelligence: Investigating Ephemeral Supply Chain Tampering

Detection coverage

SigmaHQ community rules

• Potential CVE-2026-33829 Exploitation - Windows Snipping Tool Remote File Path URI (emerging-threats)
• Potential PetitPotam Attack Via EFS RPC Calls (core)
• Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network (core)
• Possible PetitPotam Coerce Authentication Attempt (core)
• PetitPotam Suspicious Kerberos TGT Request (core)
• Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing (core)
• NTLM Hash Leak Via Curl NTLM Authentication (core)
• Attempts of Kerberos Coercion Via DNS SPN Spoofing (core)

Elastic and Splunk rules

• Active Directory Forced Authentication from Linux Host - SMB Named Pipes (elastic)
• Potential Computer Account NTLM Relay Activity (elastic)
• Potential Kerberos Relay Attack against a Computer Account (elastic)
• Potential NTLM Relay Attack against a Computer Account (elastic)
• Potential Kerberos Coercion via DNS-Based SPN Spoofing (elastic)
• Potential Kerberos SPN Spoofing via Suspicious DNS Query (elastic)
• Potential Machine Account Relay Attack via SMB (elastic)
• Rare Connection to WebDAV Target (elastic)
• Potential Local NTLM Relay via HTTP (elastic)
• Rare SMB Connection to the Internet (elastic)
• PetitPotam Network Share Access Request (splunk)
• Windows Credential Target Information Structure in Commandline (splunk)
• Windows Kerberos Coercion via DNS (splunk)
• Windows Short Lived DNS Record (splunk)
• Windows Theme File Creation in Unusual Location (splunk)
• DNS Kerberos Coercion (splunk)

Signal counts reflect the current corpus snapshot. Research citations are the technique IDs named in vendor reports and government advisories from the last 90 days; KEV mappings come from MITRE CTID. Coverage is the SigmaHQ rule inventory (core, emerging-threats, threat-hunting) at release r2026-07-01 plus Elastic and Splunk production rules. Rule bodies are not mirrored; links go upstream.