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T1556 is tampering with how authentication itself works: patched PAM modules, rogue identity-provider federation, weakened MFA enrolment, malicious certificate trust. It is the deepest form of persistence because every later login is legitimate by construction. Platform telemetry rarely catches the modification moment, and DCV's mapping is correspondingly narrow: GCP Chronicle's MODIFY_AUTHENTICATION_PROCESS rules provide the detection anchor. Treat federation changes, new token-signing certificates and MFA policy edits as change-controlled events with paging alerts; attackers who reach this layer already own a privileged identity.
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.
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 |
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.
T1556 is tampering with how authentication itself works: patched PAM modules, rogue identity-provider federation, weakened MFA enrolment, malicious certificate trust. It is the deepest form of persistence because every later login is legitimate by construction. Platform telemetry rarely catches the modification moment, and DCV's mapping is correspondingly narrow: GCP Chronicle's MODIFY_AUTHENTICATION_PROCESS rules provide the detection anchor. Treat federation changes, new token-signing certificates and MFA policy edits as change-controlled events with paging alerts; attackers who reach this layer already own a privileged identity.
DCV maps 1 cloud-native detections to T1556 across 1 cloud providers, drawn from GCP Chronicle.
T1556 is part of MITRE ATT&CK TA0112 Defense Impairment: How adversaries disable or degrade the defences that would have spotted them.
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.