Service Account Security: 5 Essential Rules Every Organization Must Follow

While organizations pay close attention to securing regular human accounts, service accounts often lack proper oversight. Yet their high level of access makes them a prime target for attackers seeking entry points into an organization’s network. 

In this article, we examine the core reasons service accounts may undermine organizational cybersecurity and outline five essential rules to help you secure your service accounts.

What are service accounts?

A service account is a privileged identity used by applications and systems. Unlike regular user accounts, service accounts don’t belong to individuals. They enable applications, services, and scripts to authenticate and operate within your IT environments without the need for human interaction. They are typically configured by system administrators or automatically created during software installation.

Service accounts can vary depending on the platform, environment, and purpose. The most common types of service accounts are:

• Local service accounts are created and managed directly on a single device or server. These accounts operate independently of a domain and cannot be used across multiple systems. Since they are not centrally managed, local service accounts are typically tied to system-level services such as logging, printing, or scheduled tasks. 
• Domain service accounts are created and managed within Active Directory (AD) and can be used across multiple systems within a domain. These accounts are often assigned to services requiring network resource access — for example, a backup solution saving data to a shared file server or a web application connecting to a central database.
• Group managed service accounts (gMSAs) are accounts provided by AD. They allow multiple systems to share the same service account credentials securely. gMSAs are typically used in environments where services run across multiple servers, such as in load-balanced applications or clustered deployments.
• Cloud service accounts are accounts used by cloud-based applications, virtual machines, and services to authenticate and access cloud resources. These accounts belong to cloud platforms like AWS, Azure, or Google Cloud and are often linked to identity and access management (IAM) policies.

Without centralized oversight, service accounts can fall prey to attackers seeking to compromise your internal systems. In the next section, we’ll explore what makes service accounts so dangerous to organizational cybersecurity.

Why do service accounts pose a risk?

Despite operating behind the scenes, service accounts are often prime targets for attackers. ReliaQuest’s incident data from early 2024 states that 85% of breaches that year involved compromised service accounts, showing a significant increase from 71% in 2023. The main reasons why organizations fail to protect service accounts against perpetrators include:

Lack of oversight

Service accounts are often created during deployments, installations, or integrations and are rarely documented properly. The absence of a comprehensive and up-to-date inventory of service accounts is a fundamental cybersecurity issue. Without this detailed inventory, you’re practically blind to the risks service accounts may pose.

As a result, your organization may have limited visibility into the number of existing service accounts, which systems they can access, and whether they’re still in use. This makes effective monitoring difficult, further increasing the risk that these accounts will be misused or compromised without detection.

Poor credential hygiene

In contrast to user accounts, service accounts are often excluded from organizational password security policies. Hence, they often rely on static, weak, or even default credentials. Users may store service account passwords in plain text, hardcode them into configuration files, or lose track of them entirely if the person in charge of them leaves the organization.

Without requirements on complexity, storage, and rotation, service account credentials become easy targets for attackers and persistent entry points into your IT environment.

Excessive permissions

Admins may grant service accounts more permissions than needed simply because they don’t know what minimum permissions are necessary to support business operations. Over time, service accounts accumulate access to sensitive systems, data, and infrastructure well beyond their intended scope. 

Thus, attackers can immediately access your organization’s most sensitive assets if a single overprivileged service account is compromised. Moreover, unjustified privileged access violates many IT security requirements, including NIS2, ISO/IEC 27001, and NIST SP 800-53.

No ownership

Many service accounts lack a clearly assigned owner, meaning that no one is responsible for managing their lifecycle or security. Over time, teams change, consultants leave, and systems evolve, but service accounts and their permissions remain unchanged.

Without ownership, no one reviews the account’s access, rotates its credentials, or validates whether the account is still needed. This lack of accountability can lead to abandoned accounts with standing privileges, which attackers can exploit with minimal resistance and little chance of detection.

Understanding the challenges of securing service accounts is essential, but awareness alone won’t protect your organization. To reduce risk, you also need to apply the core principles of effective service account security.

5 basic rules for service account security

How to secure service accounts?

Securing service accounts must be part of your cybersecurity strategy, whether you’re trying to meet compliance requirements or reduce exposure to insider threats. The following five service account security best practices outline the essential steps your organization should take to manage non-human accounts securely.

1. Inventory service accounts

A complete, up-to-date inventory is essential for maintaining visibility and control. Start by identifying and documenting all service accounts across your IT environment. With automated privileged account discovery, you can do this quickly and effectively.

Document every service account in use along with its origin, function, access permissions, and technical dependencies. Establish clear ownership by noting who is responsible for managing each account and how often those personnel should review the accounts’ access permissions and rotate their credentials.

Instituting an inventory process will give you more control over non-human identities and reduce the chance of service account exploitation.

2. Prevent interactive logins

Service accounts aren’t meant to be used by people. Allowing human users to log into service accounts defeats their purpose and introduces additional security risks. Consider disabling interactive access to service accounts whenever possible to ensure that these accounts can’t be logged into through remote desktop, SSH, or local console. 

This restriction helps enforce the principle that service accounts are non-human identities. It also prevents external attackers and internal users from misusing service account credentials to gain direct access to your IT systems. While preventing interactive logins is one of the most effective security rules, you might not be able to apply it to all service accounts.

3. Improve credential hygiene

Weak passwords are a common entry point for attackers, and service account password security is often overlooked. Develop or update your password policy to make sure it applies to service accounts. Ensure that each account has a long, unique, and complex password that isn’t reused anywhere else. Prohibit embedding credentials in scripts as well as sharing and storing passwords in unsecured channels. 

Establish a password rotation strategy. Service accounts often power critical tasks and background processes, so changing a password can sometimes interrupt workflows. That’s why it’s crucial to come up with a rotation process that’s both secure and well-coordinated. Consider using a password manager to automate the process.

Implementing secure credential hygiene best practices for service accounts reduces the risk of brute-force attacks, unauthorized access, and privilege escalation.

4. Restrict access permissions

Overprivileged accounts are a major security risk. If compromised, they give attackers broad access to critical systems and data. That’s why service accounts should never have more access than they truly need. You can start by implementing role-based access control (RBAC) to define clear, limited permissions for service accounts. Apply the principle of least privilege to grant only the minimum permissions required for each account to perform its specific tasks, and nothing more. By limiting service account access permissions, you reduce the potential radius of a breach and limit the potential for accidental or intentional misuse.

Keep track of service account access rights and ensure that no unnecessary privileges accumulate over time. Perform regular access reviews to revoke outdated or excessive privileges, thus minimizing the risks of privilege creep.

5. Monitor service accounts

Monitoring service account activity is essential for detecting unauthorized access, privilege misuse, and signs of compromise. Implement continuous monitoring to track how service accounts interact with systems, what resources they access, and when deviations from normal activity occur. Be sure to also audit any service account configuration changes, such as when account credentials or access rights are modified.

Service account monitoring not only helps detect suspicious activity early but also enhances accountability across IT teams. If an incident occurs, audit logs can show what the account did and when, enabling faster root cause analysis and containment.

Conclusion

Machine identities are essential to system operations, but without proper service account management, they become a serious liability. By applying the five fundamental rules outlined in this article, you can reduce the risk of service account misuse, improve visibility, and strengthen your organization’s security posture. However, implementing these fundamentals can be complex, often requiring the use of additional tools.

The Syteca platform is designed to help organizations enhance security inside their perimeter by providing powerful privileged access management (PAM) and user activity monitoring (UAM). Syteca’s privileged account discovery capabilities can assist you with service account inventory by identifying AD and Windows local accounts. You can even automate discovery scans to ensure that newly created accounts aren’t overlooked. Concurrent to these processes, Syteca’s real-time monitoring functionality ensures that no suspicious activity goes unnoticed.