type: attack-pattern
spec_version: 2.1
id: attack-pattern--90c4a591-d02d-490b-92aa-619d9701ac04
created: 2023-03-30T22:45:00.431Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1556/008
external_id: T1556.008
source_name: NPPSPY - Huntress
description:  Dray Agha. (2022, August 16). Cleartext Shenanigans: Gifting User Passwords to Adversaries With NPPSPY. Retrieved March 30, 2023.
url: https://www.huntress.com/blog/cleartext-shenanigans-gifting-user-passwords-to-adversaries-with-nppspy
source_name: NPPSPY Video
description: Grzegorz Tworek. (2021, December 14). How winlogon.exe shares the cleartext password with custom DLLs. Retrieved March 30, 2023.
url: https://www.youtube.com/watch?v=ggY3srD9dYs
source_name: NPPSPY
description: Grzegorz Tworek. (2021, December 15). NPPSpy. Retrieved March 30, 2023.
url: https://github.com/gtworek/PSBits/tree/master/PasswordStealing/NPPSpy
source_name: Network Provider API
description: Microsoft. (2021, January 7). Network Provider API. Retrieved March 30, 2023.
url: https://learn.microsoft.com/en-us/windows/win32/secauthn/network-provider-api
source_name: NPLogonNotify
description: Microsoft. (2021, October 21). NPLogonNotify function (npapi.h). Retrieved March 30, 2023.
url: https://learn.microsoft.com/en-us/windows/win32/api/npapi/nf-npapi-nplogonnotify
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-04-15T22:51:56.379Z
name: Network Provider DLL
description: Adversaries may register malicious network provider dynamic link libraries (DLLs) to capture cleartext user credentials during the authentication process. Network provider DLLs allow Windows to interface with specific network protocols and can also support add-on credential management functions.(Citation: Network Provider API) During the logon process, Winlogon (the interactive logon module) sends credentials to the local `mpnotify.exe` process via RPC. The `mpnotify.exe` process then shares the credentials in cleartext with registered credential managers when notifying that a logon event is happening.(Citation: NPPSPY - Huntress)(Citation: NPPSPY Video)(Citation: NPLogonNotify) 

Adversaries can configure a malicious network provider DLL to receive credentials from `mpnotify.exe`.(Citation: NPPSPY) Once installed as a credential manager (via the Registry), a malicious DLL can receive and save credentials each time a user logs onto a Windows workstation or domain via the `NPLogonNotify()` function.(Citation: NPLogonNotify)

Adversaries may target planting malicious network provider DLLs on systems known to have increased logon activity and/or administrator logon activity, such as servers and domain controllers.(Citation: NPPSPY - Huntress)
kill_chain_phases: kill_chain_name: mitre-attack
phase_name: credential-access
kill_chain_name: mitre-attack
phase_name: defense-evasion
kill_chain_name: mitre-attack
phase_name: persistence
x_mitre_attack_spec_version: 3.2.0
x_mitre_contributors: CrowdStrike Falcon OverWatch
Jai Minton
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: yes
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Windows
x_mitre_version: 1.0