The Complete Guide to Securing Service Accounts — Understanding Risks and Fixes

Read full article here: https://astrix.security/learn/blog/the-service-accounts-guide-part-1-origin-types-pitfalls-and-fixes/?utm_source=nhimg

When you hear the term “service account,” what comes to mind? Maybe it’s an unrotated password buried in a legacy database. Maybe it’s an API key with full admin rights shared across systems. Or maybe it’s the invisible glue keeping your entire infrastructure running.

Service accounts are the original non-human identities (NHIs)—silent yet powerful connectors that allow systems, applications, and scripts to authenticate and perform automated operations without human intervention. They enable automation, data exchange, and integration, but also present one of the biggest hidden security challenges inside organizations today.

This first part of the Service Accounts Guide explores their origins, how they evolved from on-prem systems to modern cloud environments, the most common pitfalls organizations face, and the steps needed to fix them.

The Origin of Service Accounts

The concept of the service account dates back to the Windows NT era. Microsoft introduced LocalSystem, a non-interactive account designed to run core system processes with elevated privileges. It could access almost everything on the machine—files, processes, registry entries, and even system-level functions.

While this design simplified management, it also created a single point of failure: if the LocalSystem account was compromised, the attacker gained full control of the system. Over time, organizations replicated this model—using privileged service accounts for automation and system operations, often without robust security guardrails.

Fast forward to today’s cloud and SaaS-driven environments, and these accounts have multiplied across infrastructure, pipelines, APIs, and containerized workloads. They’re now integral to CI/CD, DevOps, and microservices architectures. Unfortunately, they’ve inherited their legacy vulnerabilities—static credentials, overprivileged access, and lack of visibility.

The Evolution to Modern Service Accounts

Originally, service accounts were confined to single systems—managing tasks like backups or log rotation. But as organizations embraced distributed and cloud-native architectures, these accounts became crucial for connecting hundreds of microservices and APIs.

In today’s environment, service accounts are everywhere: they connect CI/CD pipelines, orchestrate Kubernetes clusters, manage SaaS integrations, and access sensitive data repositories. But as the number of accounts grows, so does the attack surface. Most organizations now operate thousands of unmanaged service accounts—many unmonitored, shared, or forgotten.

These unmanaged accounts create blind spots for security and compliance teams. Many have permissions that far exceed what’s necessary, and their credentials often lack rotation or expiration policies. In short, they’ve become the modern “keys to the kingdom” for attackers.

Types of Service Accounts

Not all service accounts are created equal. Understanding their different forms is the first step toward securing them.

1. User-Based Service Accounts

When developers need automation fast, they often take shortcuts—repurposing regular human user accounts for automated processes. These accounts inherit the permissions and privileges of human users but bypass controls like MFA or session monitoring.

This approach introduces major risks:

• Human credentials stored in scripts or pipelines
• Lack of auditability—activity appears to come from a human
• No separation of duties between automation and user access

Example: A developer uses their own corporate credentials to run automated reports every night. When they leave the company, their credentials remain active, silently executing tasks.

2. Cyborg Accounts

Cyborg accounts blend human and machine access. A user generates an API key or token tied to their personal account, enabling programmatic access while retaining human privileges.

These hybrid identities are difficult to monitor—part human, part bot. Their permissions often exceed operational needs, and they rarely expire. Worse, when a user is offboarded, the tied tokens may remain active, continuing to grant backend access.

3. Built-In Service Accounts

The safest type of service account is the purpose-built kind offered by modern platforms such as Google Cloud, Azure, or Kubernetes. These accounts are designed for automation and come with:

• Granular IAM controls
• Automatically rotating cryptographic keys
• Clear logging and traceability
• Role-based policies tied to least privilege

For example, Google Cloud’s “service accounts” can authenticate workloads securely using short-lived credentials and can be managed at scale using identity-aware policies.

Common Pitfalls of Service Account Management

Service accounts often suffer from the following recurring issues:

• Overprivileged access – Many are granted admin or root-level permissions “just to make things work.”
• Static credentials – Hardcoded passwords or API keys never rotated or expired.
• Shared usage – Multiple teams or services reuse the same credentials, making attribution impossible.
• Poor visibility – Lack of centralized inventory or monitoring, especially across multi-cloud setups.
• Insecure offboarding – Old service accounts remain active even after the associated service or user is deprecated.

These pitfalls create conditions ripe for exploitation. Attackers know that unused, unmonitored service accounts are often the easiest way into critical systems.

How to Fix the Service Account Problem

The path to secure service accounts lies in a combination of visibility, automation, and governance.

1. Detect Misused or “Cyborg” Accounts

Use IAM analytics, audit logs, and anomaly detection tools to identify user accounts performing automated actions. Look for unusual behavior, such as API calls from a human account or access outside normal working hours.

2. Provide Secure Automation Alternatives

Empower developers and DevOps teams with properly managed, built-in service accounts that are easy to create and use. Streamlining secure automation options discourages insecure workarounds.

3. Educate and Enforce

Raise awareness about the dangers of misusing user accounts for automation. Implement clear policies and training to ensure teams know when and how to use dedicated service accounts.

4. Automate Lifecycle Management

Establish automated creation, rotation, and deactivation workflows for service accounts. This ensures credentials don’t linger long after their purpose is fulfilled.

5. Conduct Regular Access Reviews

Schedule quarterly reviews to validate that service accounts follow least-privilege principles and remain active only when needed.

Final Thoughts

Service accounts may be among the oldest forms of machine identity, but they remain one of the most misunderstood and mismanaged. As organizations scale automation, service account sprawl becomes a silent security risk—fueling privilege escalation, insider threats, and lateral movement.

By shifting from ad hoc user-based automation to well-governed, purpose-built service accounts with centralized management, continuous monitoring, and automated lifecycle control, organizations can drastically reduce risk.

Securing service accounts isn’t just an operational task—it’s a foundational step in any modern Non-Human Identity Security (NHI) and Workload IAM strategy.