Why do service accounts and other NHIs often create hidden exposure?

Why This Matters for Security Teams

service account, API keys, and other NHIs are often the shortest path to valuable systems because they are designed for automation, not human oversight. That makes them easy to undercount, overtrust, and leave in place long after the original use case has changed. NHI Management Group research shows how serious the visibility problem is: only 5.7% of organisations have full visibility into their service accounts, and 97% of NHIs carry excessive privileges in many environments, as covered in the Ultimate Guide to NHIs.

The operational risk is not just exposure at rest. Hidden NHIs frequently sit outside normal joiner-mover-leaver processes, so their permissions expand quietly while monitoring remains focused on named users. That creates a blind spot for investigations, especially when secrets are stored in code, CI/CD systems, or scattered across tools. This is why current guidance increasingly treats NHIs as first-class identities rather than “technical accounts” that can be exempt from governance. The problem is also visible in breach patterns documented in the 52 NHI Breaches Analysis, where hidden credentials repeatedly enabled access that defenders did not realise existed. In practice, many security teams encounter NHI exposure only after privilege misuse or secret leakage has already occurred, rather than through intentional review.

How It Works in Practice

Hidden exposure emerges when service accounts are created to solve a narrow operational need, then accumulate permissions, integrations, and long-lived secrets over time. The account may be used by an application, a CI/CD pipeline, a backup job, or a third-party integration, but it still needs a clear owner, lifecycle, and revocation path. If those controls are missing, the account becomes durable access with little accountability. This is especially risky because attackers now target identity pathways directly, including automated tooling and outsourced workflows, as discussed in Anthropic's report on an AI-orchestrated cyber espionage campaign.

Security teams should treat hidden exposure as a lifecycle problem, not just a permissions problem. Practical controls include:

• Inventory all service accounts, API keys, OAuth apps, and workload identities in one register.
• Assign an accountable owner, business purpose, and expiration date to each identity.
• Replace static secrets with short-lived credentials wherever the platform allows.
• Review privileges against actual runtime use, not just the original request ticket.
• Detect stale identities, dormant tokens, and secrets that still validate after decommissioning.

Visibility work should also extend to third-party connections and automation paths, because hidden exposure often sits in vendor integrations rather than core infrastructure. NHIMG’s State of Non-Human Identity Security research highlights that many organisations still lack full visibility into third-party OAuth-connected access, which means exposure can persist outside the direct control of the security team. When accounts are not tied to a dependable owner and revocation process, they tend to survive application changes, team changes, and tool changes, then quietly outlive the systems they were meant to support. These controls tend to break down in fast-moving DevOps environments because account creation is automated but accountability and offboarding remain manual.

Common Variations and Edge Cases

Tighter NHI governance often increases operational overhead, requiring organisations to balance automation speed against control depth. That tradeoff matters because some NHIs are intentionally persistent, such as infrastructure agents or scheduled jobs, while others should be ephemeral by design. Best practice is evolving toward shorter-lived secrets and stronger workload identity, but there is no universal standard for every environment yet.

Edge cases usually appear where platform constraints force compromise. Legacy applications may only support static credentials, and some third-party tools do not expose enough telemetry to prove how a service account is actually used. In those environments, teams should compensate with compensating controls such as stricter rotation, tighter scope, segmentation, and alerting on unusual authentication patterns. It is also common for one identity to serve multiple purposes, which blurs ownership and makes access reviews misleading. That is why guidance from NHI Management Group research should be paired with implementation standards such as Top 10 NHI Issues and platform-level visibility measures rather than assuming one policy will fit every workload. Current guidance suggests treating any shared, over-privileged, or non-expiring service account as a candidate for redesign, even if immediate replacement is not practical.

Related resources from NHI Mgmt Group

• Why do service accounts and other NHIs create problems for GRC programmes?
• Why does UEBA often struggle with service accounts and other NHIs?
• Why do service accounts and other non-human identities create hidden risk in IAM programmes?
• Why do non-human identities create more risk than many human accounts?