Live Active security incident? Get immediate response
MITRE ATT&CK® Technique

T1556: Modify Authentication Process

Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts. The authentication process is handled by mechanisms, such as the Local Security Authentication Server (LSASS) process and the Security Accounts Manager (SAM) on Windows, pluggable authentication modules (PAM) on Unix-based systems, and authorization plugins on MacOS systems, responsible for gathering, storing, and validating credentials. By modifying an authentication process, an adversary may be able to authenticate to a service or system without using Valid Accounts.

Adversaries may maliciously modify a part of this process to either reveal credentials or bypass authentication mechanisms. Compromised credentials or access may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access and remote desktop.

EnterpriseT1556TechniqueObject v3.0 Modified
Glexia's Take

Analyst context for executives and security teams

Analyst confidence High

Modify Authentication Process matters because it targets the trust layer that decides who is allowed in. If an adversary can alter authentication components, they may capture credentials, bypass normal login controls, or preserve access without relying on ordinary valid account use. For leaders, this is an identity resilience issue across Windows, Linux, macOS, network devices, SaaS, IaaS, office suites, and identity providers—not just an endpoint hardening concern.

Executive priority

Prioritize this technique where authentication systems are business-critical: domain controllers, identity providers, VPN or remote access paths, cloud identity integrations, network devices, and externally reachable services. The key executive question is whether the organization can prove authentication mechanisms are hardened, monitored for unauthorized change, and recoverable during an incident. This also supports audit and compliance evidence because mitigations include account management, privileged account management, MFA, permission restriction, OS configuration, and auditing.

Technical view

ATT&CK maps T1556 to defense impairment, persistence, and credential access. SOC, detection engineering, and IR teams should validate monitoring for unauthorized changes to authentication components across the supported platforms. Relationship context shows sub-techniques for Windows domain controller authentication, password filter DLLs, network provider DLLs, reversible encryption, Linux/macOS PAM, network device authentication, MFA modification, hybrid identity, and conditional access policy modification. Because official detection text is not provided, teams should use DET0104, Detect Modification of Authentication Processes Across Platforms, as the ATT&CK-linked detection strategy and test coverage against local authentication architectures.

Likely telemetry

  • Windows security and system events related to authentication configuration, privileged process changes, registry changes, password filter DLLs, network provider DLLs, LSASS/SAM-adjacent activity, and domain controller configuration changes
  • Linux and macOS file integrity, package/configuration, and authentication logs covering PAM files, shared libraries, authorization plugins, and SSH-related authentication components
  • Identity provider, IaaS, SaaS, and office suite audit logs for MFA settings, conditional access policy changes, hybrid identity configuration changes, and privileged identity administration
  • Network device configuration, firmware or system image integrity evidence, authentication configuration changes, and administrative access logs
  • Privileged account activity logs showing who changed authentication controls, when, from where, and through which administrative path

Detection direction

  • Confirm that changes to authentication mechanisms generate alertable events, not just audit records retained for later review.
  • Tune detections around high-risk change points: domain controllers, identity providers, hybrid identity synchronization paths, MFA and conditional access controls, PAM configuration, authentication DLL registration, and network device authentication images or settings.
  • Correlate authentication-process changes with privileged account activity, new persistence indicators, unusual remote access success, and credential-access alerts.
  • Account for legitimate administrative maintenance, OS upgrades, identity policy changes, and network device patching as common false-positive sources; require change-ticket or approved-administrator context where available.
  • Treat absence of official ATT&CK detection text as a coverage gap to validate through local engineering and ATT&CK detection strategy DET0104 rather than assuming tool coverage.

Mitigation priorities

  • Start with auditing: maintain evidence of authentication configuration baselines and review changes on all critical systems and identity platforms.
  • Restrict file, directory, and registry permissions around authentication components so only authorized administrative paths can modify them.
  • Strengthen privileged account and user account management with least privilege, lifecycle controls, and accountability for administrative changes.
  • Apply privileged process integrity and operating system configuration hardening where supported to reduce tampering with authentication-related processes and services.
  • Use MFA and strong password policies, while also monitoring for changes to MFA, reversible encryption, and conditional access controls because this technique can target those defenses directly.
Analyst notes and limits

The relationship set broadens the practical scope from host authentication to identity-provider and cloud-connected authentication controls. ATT&CK also relates this technique to ArcaneDoor, FIN13, Ebury, Kessel, and SILENTTRINITY, indicating that multiple campaign, group, and software entries have used or are mapped to this behavior; this should inform threat-informed validation without implying current exposure in any specific environment.

Official detection text for T1556 is not provided. The supplied data identifies platforms, tactics, mitigations, a detection strategy relationship, and sub-technique context, but local architecture determines which authentication components exist and which telemetry is available. This take does not assert active exploitation, customer impact, or guaranteed detection coverage.

Official MITRE ATT&CK definition

Modify Authentication Process

Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts. The authentication process is handled by mechanisms, such as the Local Security Authentication Server (LSASS) process and the Security Accounts Manager (SAM) on Windows, pluggable authentication modules (PAM) on Unix-based systems, and authorization plugins on MacOS systems, responsible for gathering, storing, and validating credentials. By modifying an authentication process, an adversary may be able to authenticate to a service or system without using Valid Accounts.

Adversaries may maliciously modify a part of this process to either reveal credentials or bypass authentication mechanisms. Compromised credentials or access may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access and remote desktop.

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

Glexia analysis

How security teams should use this page

Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.

ATT&CK relationship table

Related techniques

This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.

9 rows
Domain ID Name Relationship / procedure
Enterprise T1556.004 Network Device Authentication Sub-technique Network Device Authentication subtechnique of this object.
Enterprise T1556.001 Domain Controller Authentication Sub-technique Domain Controller Authentication subtechnique of this object.
Enterprise T1556.009 Conditional Access Policies Sub-technique Conditional Access Policies subtechnique of this object.
Enterprise T1556.008 Network Provider DLL Sub-technique Network Provider DLL subtechnique of this object.
Enterprise T1556.002 Password Filter DLL Sub-technique Password Filter DLL subtechnique of this object.
Enterprise T1556.006 Multi-Factor Authentication Sub-technique Multi-Factor Authentication subtechnique of this object.
Enterprise T1556.007 Hybrid Identity Sub-technique Hybrid Identity subtechnique of this object.
Enterprise T1556.005 Reversible Encryption Sub-technique Reversible Encryption subtechnique of this object.
Enterprise T1556.003 Pluggable Authentication Modules Sub-technique Pluggable Authentication Modules subtechnique of this object.
Associated objects

Groups, software, and campaigns

Group Enterprise

G1016: FIN13

FIN13 is a financially motivated cyber threat group that has targeted the financial, retail, and hospitality industries in Mexico and Latin America, as early as 2016. FIN13 achieves its objectives by stealing intellectual property, financial data, mergers and acquisition information, or PII.[1][2]

Malware Enterprise

S0377: Ebury

Ebury is an OpenSSH backdoor and credential stealer targeting Linux servers and container hosts developed by Windigo. Ebury is primarily installed through modifying shared libraries (`.so` files) executed by the legitimate OpenSSH program. First seen in 2009, Ebury has been used to maintain a botnet of servers, deploy additional malware, and steal cryptocurrency wallets, credentials, and credit card details.[1][2][3][4]

Linux
Tool Enterprise

S0692: SILENTTRINITY

SILENTTRINITY is an open source remote administration and post-exploitation framework primarily written in Python that includes stagers written in Powershell, C, and Boo. SILENTTRINITY was used in a 2019 campaign against Croatian government agencies by unidentified cyber actors.[1][2]

Windows
Malware Enterprise

S0487: Kessel

Kessel is an advanced version of OpenSSH which acts as a custom backdoor, mainly acting to steal credentials and function as a bot. Kessel has been active since its C2 domain began resolving in August 2018.[1]

Linux
Malware Enterprise

S9013: DRYHOOK

DRYHOOK is Python script used to steal credentials. DRYHOOK was first reported in January 2025, and has previously been leveraged by People's Republic of China (PRC) state-affiliated threat actors identified as UNC5221 and SYLVANITE.[1][2][3]

LinuxNetwork Devices
Campaign Enterprise

C0046: ArcaneDoor

ArcaneDoor is a campaign targeting networking devices from Cisco and other vendors between July 2023 and April 2024, primarily focused on government and critical infrastructure networks. ArcaneDoor is associated with the deployment of the custom backdoors Line Runner and Line Dancer. ArcaneDoor is attributed to a group referred to as UAT4356 or STORM-1849, and is assessed to be a state-sponsored campaign.[1][2]

Relationship explorer

All related ATT&CK context

subtechnique of · Technique T1556.004: Network Device Authentication Enterprise subtechnique of · Technique T1556.001: Domain Controller Authentication Enterprise mitigates · Mitigation M1024: Restrict Registry Permissions Enterprise mitigates · Mitigation M1032: Multi-factor Authentication Enterprise subtechnique of · Technique T1556.009: Conditional Access Policies Enterprise subtechnique of · Technique T1556.008: Network Provider DLL Enterprise subtechnique of · Technique T1556.002: Password Filter DLL Enterprise uses · Malware S0377: Ebury Enterprise mitigates · Mitigation M1027: Password Policies Enterprise uses · Tool S0692: SILENTTRINITY Enterprise uses · Malware S0487: Kessel Enterprise uses · Campaign C0046: ArcaneDoor Enterprise mitigates · Mitigation M1022: Restrict File and Directory Permissions Enterprise subtechnique of · Technique T1556.006: Multi-Factor Authentication Enterprise subtechnique of · Technique T1556.007: Hybrid Identity Enterprise uses · Malware S9013: DRYHOOK Enterprise subtechnique of · Technique T1556.005: Reversible Encryption Enterprise detects · Detection Strategy DET0104: Detect Modification of Authentication Processes Across Platforms Enterprise mitigates · Mitigation M1018: User Account Management Enterprise mitigates · Mitigation M1026: Privileged Account Management Enterprise uses · Group G1016: FIN13 Enterprise subtechnique of · Technique T1556.003: Pluggable Authentication Modules Enterprise mitigates · Mitigation M1025: Privileged Process Integrity Enterprise mitigates · Mitigation M1047: Audit Enterprise
Mitigations

Mitigation direction

Change history

Object version and sync metadata

The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates .

ATT&CK release
19.1
Object version
3.0
Created
Modified
Raw hash
cebad3044733d46f...
Imported snapshots across ATT&CK releases (1)
Release Bundle imported Object version Modified Status Raw hash
19.1 3.0 Current bundle cebad3044733…
Raw source

Mirrored ATT&CK source object

The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.

Source references

External references and citations

MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.

  1. [1]
    mitre-attack T1556
    Open source URL
Source and licensing

Source: MITRE ATT&CK®. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. MITRE ATT&CK and ATT&CK are registered trademarks of The MITRE Corporation. Glexia is not affiliated with or endorsed by MITRE.