MITRE ATT&CK · TA0003 Persistence

T1556: Modify Authentication Process

Last reviewed:

Detection coverage in DCV across AWS, Azure and GCP for Modify Authentication Process, plus the corresponding Sigma rules in the CloudSigma library. Source data refreshed 2026-05-21.

01 What is T1556?

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.

Platforms: IaaS, Identity Provider, Linux, macOS, Network Devices, Office Suite, SaaS, Windows.

02 Coverage in DCV

DCV maps 1 detection across 1 cloud provider to T1556. Coverage by source:

Source Cloud Findings mapped Avg confidence
GCP Chronicle GCP 1 0.85

03 Detect with CloudSigma

CloudSigma has coverage metadata for 1 T1556 rule across 3 platforms. The linked platform page remains the canonical rule surface; this page will embed an example after a rule clears the public embed bar.

CloudSigma has coverage metadata for T1556, but no public example rule clears the embed bar for this page yet. Generate a fresh starting-point rule in CloudSigma from the relevant advisory or threat-research input, then validate it against your local telemetry before enabling it in production.

05 Related techniques

06 FAQ

What is T1556 (Modify Authentication Process)?

Detection coverage in DCV across AWS, Azure and GCP for Modify Authentication Process, plus the corresponding Sigma rules in the CloudSigma library. Source data refreshed 2026-05-21.

Where does T1556 appear in cloud detection sources?

DCV maps 1 cloud-native detections to T1556 across 1 cloud providers, drawn from GCP Chronicle.

What MITRE ATT&CK tactic does T1556 belong to?

T1556 is part of MITRE ATT&CK TA0003 Persistence: How adversaries keep their foothold across reboots and credential rotations.

How does CloudSigma fit for T1556?

CloudSigma ships 3 validated Sigma rules for T1556 across AWS CloudTrail, Azure Activity and GCP Audit Logs. Each rule is validated against its source SIEM dialect before publication.

Sources
  • MITRE ATT&CK, https://attack.mitre.org/techniques/T1556/
  • MITRE Tactic TA0003 Persistence, https://attack.mitre.org/tactics/TA0003/
  • MITRE Center for Threat-Informed Defense, Security Stack Mappings (https://center-for-threat-informed-defense.github.io/security-stack-mappings/)
Last verified: 2026-05-21