Executive Summary
Modify Authentication Process (T1556) is a MITRE ATT&CK technique associated with Defense Impairment, Persistence, Credential Access. Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts.
Why Attackers Use It
Attackers use Modify Authentication Process because it provides a reliable way to advance their objective within the Defense Impairment, Persistence, Credential Access tactic, often with a favorable balance of impact versus detectability on IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, SaaS, Windows environments. Defenders should assess this behavior in the context of the affected platform and adjacent activity rather than treating it as a standalone indicator.
MITRE Description
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.
Attack Flow
- Attacker gains the prerequisite access or context described below.
- Attacker executes Modify Authentication Process to achieve its tactical objective (Defense Impairment, Persistence, Credential Access).
- Resulting access/data/effect is leveraged to advance the broader attack chain (see Related Techniques).
Prerequisites
- Platform(s): IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, SaaS, Windows
- ATT&CK does not define one universal permission requirement for this technique. Establish the required access from the observed implementation and affected platform.
Common Tools
- Tool attribution is implementation-specific. Use ATT&CK procedure examples and local telemetry to identify the binaries, services, scripts, accounts, or cloud resources involved.
Commands
No universal command represents Modify Authentication Process. Capture the exact command line, arguments, parent process, account, host, and execution time from the investigated environment; do not operationalize unverified examples.
Network Traffic
- Network observability is implementation-dependent. Review DNS, proxy, firewall, flow, authentication, and packet telemetry around the activity window, then correlate remote endpoints and protocol behavior with host evidence.
Windows Events
| Event ID | Log Channel | What It Indicates |
|---|
| Environment-specific | Relevant Windows channel(s) | Correlate authentication, process, object-access, and configuration events with the observed execution context. |
Sysmon Events
| Sysmon Event ID | Name | Why It's Relevant Here |
|---|
| Environment-specific | Validate configured telemetry | Use process, network, file, registry, DNS, or image-load telemetry only when relevant and enabled. |
Detection Opportunities
No MITRE detection guidance published for this technique.
Relevant ATT&CK Data Sources: N/A
Sigma Rules
A universal Sigma rule would create unreliable results because this technique has no single guaranteed observable. Build detection logic from a documented behavior and supported data source, scope it to the affected platform, and validate it against benign administrative activity before deployment.
Splunk Queries
Start with the data sources named in the detection section. Scope searches by asset, identity, and time window; correlate the primary behavior with preceding access and subsequent actions. A portable query is intentionally not provided where the technique lacks a universal schema or observable.
Investigation Workflow
- Confirm that the observed behavior is consistent with Modify Authentication Process and rule out expected administrative or application activity.
- Establish the first-seen time, initiating identity, source system, target system, and affected resources.
- Collect relevant host, identity, network, cloud, and application telemetry for the surrounding time window.
- Correlate parent and child activity, remote connections, file or configuration changes, and related ATT&CK techniques.
- Determine scope by searching for the same observable across peer assets and identities.
- Preserve volatile evidence and record confidence, assumptions, and telemetry gaps before containment.
Containment
- Isolate affected host(s)/account(s) identified during investigation.
- Revoke or rotate any credentials/tokens potentially exposed.
- Apply the mitigations listed below where not already enforced.
- Validate no related techniques (see Related Techniques) were chained against the same asset.
Mitigation
- M1024 -- Restrict Registry Permissions: Restricting registry permissions involves configuring access control settings for sensitive registry keys and hives to ensure that only authorized users or processes can make modifications.
- M1032 -- Multi-factor Authentication: Multi-Factor Authentication (MFA) enhances security by requiring users to provide at least two forms of verification to prove their identity before granting access.
- M1027 -- Password Policies: Set and enforce secure password policies for accounts to reduce the likelihood of unauthorized access.
- M1022 -- Restrict File and Directory Permissions: Restricting file and directory permissions involves setting access controls at the file system level to limit which users, groups, or processes can read, write, or execute files.
- M1018 -- User Account Management: User Account Management involves implementing and enforcing policies for the lifecycle of user accounts, including creation, modification, and deactivation.
- M1026 -- Privileged Account Management: Privileged Account Management focuses on implementing policies, controls, and tools to securely manage privileged accounts (e.g., SYSTEM, root, or administrative accounts).
- M1025 -- Privileged Process Integrity: Privileged Process Integrity focuses on defending highly privileged processes (e.g., system services, antivirus, or authentication processes) from tampering, injection, or compromise by adversaries.
- M1047 -- Audit: Auditing is the process of recording activity and systematically reviewing and analyzing the activity and system configurations.
- M1028 -- Operating System Configuration: Operating System Configuration involves adjusting system settings and hardening the default configurations of an operating system (OS) to mitigate adversary exploitation and prevent abuse of system functionality.
Related Techniques
- T1014
- T1020
- T1027.013
- T1041
- T1059
- T1059.006
- T1140
- T1556.001
- T1556.002
- T1556.003
- T1556.004
- T1556.005
- T1556.006
- T1556.007
- T1556.008
- T1556.009
- T1685