Why do unused cloud services create both cost and security risk?

Why This Matters for Security Teams

Unused cloud services are not just wasted spend. They are ungoverned capabilities that can still expose APIs, identity paths, data stores, and privileged control planes. That makes them a dual problem: budget leakage and security blind spots. NIST Cybersecurity Framework 2.0 treats asset visibility and governance as foundational, because security teams cannot reduce risk if they cannot see what is actually deployed. In the cloud, a dormant service is still part of the attack surface.

The risk grows when service sprawl outpaces inventory discipline. A team may believe a capability is disabled, while its secrets, roles, or network paths remain active. NHIMG research on the 2024 ESG Report: Managing Non-Human Identities found that 72% of organisations have experienced or suspect a breach of non-human identities, which is a strong signal that hidden or poorly governed service identities are already being exploited. That pattern aligns with the broader NHI failure mode described in Top 10 NHI Issues.

In practice, many security teams encounter exposure only after a forgotten service is abused for access, rather than through intentional retirement controls.

How It Works in Practice

An unused service becomes risky when its lifecycle is incomplete. Decommissioning is not just stopping traffic; it should remove identities, revoke secrets, detach roles, close network exposure, and update asset registers. If any of those steps are skipped, the service may no longer be business-critical but it still exists as a valid target. That is why cloud cost management and identity governance need to operate together, not as separate workstreams.

Effective teams build a retirement workflow around evidence, not assumptions. They verify whether the service still has active credentials, whether its API endpoints are reachable, whether logs show recent use, and whether the owning team can attest to business need. Controls such as privileged access review, secret rotation, and automated expiration are essential here. The NIST Cybersecurity Framework 2.0 is useful for structuring the inventory and governance side, while NHIMG guidance in Ultimate Guide to NHIs explains why non-human identities often persist long after the workload is forgotten.

• Track every service with an owner, purpose, expiry date, and associated identity artifacts.
• Revoke service accounts, API keys, certificates, and tokens when the service is retired.
• Remove unused permissions and disable network paths before marking a service inactive.
• Feed cloud inventory into FinOps and security reviews so stale assets are flagged quickly.

These controls tend to break down in multi-account cloud environments with manual handoffs because ownership, identity cleanup, and billing reconciliation rarely happen at the same speed.

Common Variations and Edge Cases

Tighter decommissioning controls often increase operational overhead, requiring organisations to balance reduced attack surface against the cost of stronger lifecycle governance. Not every unused service is equally dangerous. A disabled dev environment with no secrets is lower risk than a retired production API that still holds long-lived credentials or has access to regulated data. Best practice is evolving, but current guidance suggests prioritising services with privileged identities, external exposure, or links to sensitive datasets first.

There is also a distinction between truly unused and merely quiet. Some services run on low-volume schedules, which makes them easy to misclassify as dormant. Others are “shadow dependencies” that remain necessary for integrations no one owns clearly. Those cases need business validation before removal, because aggressive cleanup can cause outages. The practical answer is to couple service retirement with identity hygiene and continuous discovery, not one-time cleanup.

NHIMG’s The 2026 Infrastructure Identity Survey reported that 67% of organisations still rely heavily on static credentials despite the risks they pose to agentic AI deployments. That matters here because the same static secrets that survive service retirement also make forgotten services easier to abuse. In security reviews, the most expensive “unused” service is often the one that still has a valid path into production.

Related resources from NHI Mgmt Group

• Why do managed cloud services still create application security risk?
• Why do dormant accounts create both cost and security risk?
• Why do unsanctioned SaaS apps create both security and cost risk?
• Why do unused SaaS accounts create security risk?