type: attack-pattern
spec_version: 2.1
id: attack-pattern--b77cf5f3-6060-475d-bd60-40ccbf28fdc2
created: 2018-01-16T16:13:52.465Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1187
external_id: T1187
source_name: Rapid7
description: Condon, Caitlin. (2022, April 24). PetitPotam: Novel Attack Chain Can Fully Compromise Windows Domains. Retrieved May 30, 2025.
url: https://www.rapid7.com/blog/post/2021/08/03/petitpotam-novel-attack-chain-can-fully-compromise-windows-domains-running-ad-cs/
source_name: Cylance Redirect to SMB
description: Cylance. (2015, April 13). Redirect to SMB. Retrieved December 21, 2017.
url: https://www.cylance.com/content/dam/cylance/pdfs/white_papers/RedirectToSMB.pdf
source_name: GitHub Hashjacking
description: Dunning, J. (2016, August 1). Hashjacking. Retrieved December 21, 2017.
url: https://github.com/hob0/hashjacking
source_name: Microsoft Managing WebDAV Security
description: Microsoft. (n.d.). Managing WebDAV Security (IIS 6.0). Retrieved November 17, 2024.
url: https://web.archive.org/web/20100210125749/https://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/4beddb35-0cba-424c-8b9b-a5832ad8e208.mspx
source_name: Osanda Stealing NetNTLM Hashes
description: Osanda Malith Jayathissa. (2017, March 24). Places of Interest in Stealing NetNTLM Hashes. Retrieved January 26, 2018.
url: https://osandamalith.com/2017/03/24/places-of-interest-in-stealing-netntlm-hashes/
source_name: Didier Stevens WebDAV Traffic
description: Stevens, D. (2017, November 13). WebDAV Traffic To Malicious Sites. Retrieved December 21, 2017.
url: https://blog.didierstevens.com/2017/11/13/webdav-traffic-to-malicious-sites/
source_name: GitHub
description: topotam. (2021, July 18). PetitPotam. PoC tool to coerce Windows hosts to authenticate to other machines. Retrieved May 30, 2025.
url: https://github.com/topotam/PetitPotam
source_name: US-CERT APT Energy Oct 2017
description: US-CERT. (2017, October 20). Alert (TA17-293A): Advanced Persistent Threat Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved November 2, 2017.
url: https://www.us-cert.gov/ncas/alerts/TA17-293A
source_name: Wikipedia Server Message Block
description: Wikipedia. (2017, December 16). Server Message Block. Retrieved December 21, 2017.
url: https://en.wikipedia.org/wiki/Server_Message_Block
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-10-24T17:49:16.134Z
name: Forced Authentication
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.

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 file[:]//[remote address]/Normal.dotm 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 \\[remote address]\pic.png 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 EfsRpcOpenFileRaw 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 EfsRpcOpenFileRaw 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 a NTLM relay attack to gain access to remote systems on the same internal network.(Citation: Rapid7)(Citation: GitHub)


kill_chain_phases: kill_chain_name: mitre-attack
phase_name: credential-access
x_mitre_attack_spec_version: 3.3.0
x_mitre_contributors: Teodor Cimpoesu
Sudhanshu Chauhan, @Sudhanshu_C
Jiraput Thamsongkrah
Purinut Wongwaiwuttiguldej
Natthawut Saexu
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: no
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Windows
x_mitre_version: 1.4