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MITRE ATT&CK® Technique

T1174: Password Filter DLL

Windows password filters are password policy enforcement mechanisms for both domain and local accounts. Filters are implemented as dynamic link libraries (DLLs) containing a method to validate potential passwords against password policies. Filter DLLs can be positioned on local computers for local accounts and/or domain controllers for domain accounts.

Before registering new passwords in the Security Accounts Manager (SAM), the Local Security Authority (LSA) requests validation from each registered filter. Any potential changes cannot take effect until every registered filter acknowledges validation.

Adversaries can register malicious password filters to harvest credentials from local computers and/or entire domains. To perform proper validation, filters must receive plain-text credentials from the LSA. A malicious password filter would receive these plain-text credentials every time a password request is made. [1]

EnterpriseT1174TechniqueObject v1.1 Modified
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Glexia's Take

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Official MITRE ATT&CK definition

Password Filter DLL

Windows password filters are password policy enforcement mechanisms for both domain and local accounts. Filters are implemented as dynamic link libraries (DLLs) containing a method to validate potential passwords against password policies. Filter DLLs can be positioned on local computers for local accounts and/or domain controllers for domain accounts.

Before registering new passwords in the Security Accounts Manager (SAM), the Local Security Authority (LSA) requests validation from each registered filter. Any potential changes cannot take effect until every registered filter acknowledges validation.

Adversaries can register malicious password filters to harvest credentials from local computers and/or entire domains. To perform proper validation, filters must receive plain-text credentials from the LSA. A malicious password filter would receive these plain-text credentials every time a password request is made. [1]

View the same entry on attack.mitre.org (MITRE-hosted reference; in-page links above use the Glexia ATT&CK library.)

Glexia analysis

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ATT&CK relationship table

Related techniques

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1 rows
Domain ID Name Relationship / procedure
Enterprise T1556.002 Password Filter DLL Sub-technique This object revoked by Password Filter DLL.
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Change history

Object version and sync metadata

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ATT&CK release
19.1
Object version
1.1
Created
Modified
Raw hash
557227df9901b28d...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 1.1 Current bundle Revoked 557227df9901…
Raw source

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Source references

External references and citations

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  1. [1]
    Carnal Ownage Password Filters Sept 2013

    Fuller, R. (2013, September 11). Stealing passwords every time they change. Retrieved November 21, 2017.

    Open source URL
  2. [2]
    Clymb3r Function Hook Passwords Sept 2013

    Bialek, J. (2013, September 15). Intercepting Password Changes With Function Hooking. Retrieved November 21, 2017.

    Open source URL
  3. [3]
    mitre-attack T1174
    Open source URL
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