What Are Shared Local Admin Credentials?

Shared Local Admin Credentials Explained

The practice of sharing local administrator credentials typically stems from legacy operational habits. In many IT environments, sysadmins historically configured a "standard" local admin account on every workstation and server to facilitate easy troubleshooting and remote maintenance. While this simplifies the workflow for help desk personnel, it effectively removes the "internal firewalls" that protect a network during a breach.

In a modern threat landscape, this configuration is a high-impact vulnerability. When an attacker gains initial access—often through a phishing link or an unpatched browser—they aim to dump the credentials stored in the local memory (LSASS). If the local admin password is the same across the fleet, the attacker no longer needs to hunt for new vulnerabilities. They simply "log in" to the next machine.

This issue is particularly dangerous because it facilitates pass-the-hash (PtH) and SMB-based attacks. By utilizing built-in Windows tools like PsExec or WMI, an adversary can execute code remotely across hundreds of machines in seconds. Eliminating shared credentials is not just a password management task; it is a fundamental requirement for achieving a zero trust architecture and containing breaches at the point of origin.

Why Shared Local Admin Credentials Are a Critical Risk

Shared credentials transform a localized incident into an organizational catastrophe by eliminating the technical barriers between endpoints. When every machine "trusts" the same secret, compromising a single low-value workstation grants access to the entire server room.

Enabling Rapid Lateral Movement

Lateral movement is the process by which attackers move from an entry point to the rest of the network. Shared credentials are the fuel for this movement. Adversaries use tools like Mimikatz to extract the NTLM hash of the local administrator from one machine and then "replay" that hash to gain access to others. Because the credentials match, the target system accepts the hash as valid, allowing the attacker to establish a remote session without knowing the actual password.

Bypassing Multi-Factor Authentication (MFA)

Most organizations focus MFA efforts on external access points, such as VPNs or email. However, local administrative logins via protocols such as SMB or WMI rarely require MFA. By exploiting shared local credentials, attackers bypass the modern identity protections that executives rely on. Once inside, the attacker operates within a "blind spot" where traditional identity challenges are absent.

The Blast Radius of a Single Compromised Endpoint

In a secure environment, a compromised laptop is an isolated problem. In an environment with shared local admin credentials, that laptop is a gateway. Palo Alto Networks Unit 42 has observed that attackers can move from a single workstation compromise to full Domain Admin privileges in less than an hour when shared credentials or cached high-privilege sessions are present. This massive "blast radius" makes it nearly impossible for incident response teams to contain the threat before data exfiltration begins.

How Attackers Exploit Shared Credentials (The Kill Chain)

Understanding the mechanics of a credential-based attack is essential for practitioners to build effective defenses. The process is highly predictable and relies on the inherent trust built into the Windows authentication architecture.

Initial Compromise and Local Privilege Escalation

The attack begins with an entry point, typically through a phishing email or a drive-by download. Once the attacker has a foothold as a standard user, they seek to escalate to local administrator. They may exploit a local kernel vulnerability or misconfigured service permissions. Once they become the local admin on the first machine, they have the necessary permissions to access the operating system's credential store.

Credential Dumping (LSASS and SAM)

With local admin rights, the attacker targets the Local Security Authority Subsystem Service (LSASS) memory or the Security Account Manager (SAM) database. Tools like Mimikatz or built-in Windows commands can dump the NTLM hashes of any account that has logged into that machine. If the local administrator account is active and has a shared password, its hash is now in the attacker's possession.

Pass-the-Hash (PtH) and SMB Lateral Movement

The attacker does not need to crack the dumped hash to use it. Using the Pass-the-Hash technique, they present the hash to other systems on the network via the Server Message Block (SMB) protocol. If those systems share the same local admin password, the attacker will gain administrative access. This allows the attacker to execute commands remotely, install persistent backdoors, and hunt for Domain Admin credentials cached on servers.

Critical Statistics: The Impact of Credential Reuse

Data from global incident response engagements highlights that credential issues remain the primary driver of successful breaches.

Unit 42 Insights on Lateral Movement Trends

Recent research from Unit 42 indicates that lateral movement is present in nearly 80% of successful ransomware attacks. In these cases, the use of legitimate credentials—rather than exploits—is the preferred method for spreading the payload. Organizations that fail to implement unique local passwords experience a significantly lower rate of complete environment encryption than those with unique, rotating credentials.

CISA Findings on Critical Infrastructure Vulnerabilities

The Cybersecurity and Infrastructure Security Agency (CISA) frequently cites shared administrative passwords as a top finding in its Risk and Vulnerability Assessments (RVAs). In many audited environments, CISA teams were able to gain full network control starting from a single unprivileged workstation by simply "hopping" between systems using shared local administrative accounts.

How to Prevent Shared Credential Vulnerabilities

Defending against this threat requires moving away from static, manual password management and adopting automated, policy-driven controls.

Implementing Windows Local Administrator Password Solution (LAPS)

Microsoft LAPS is the industry-standard tool for managing local administrator passwords. It automatically generates a unique, complex password for the local admin account on every domain-joined machine and stores it as a protected attribute in Active Directory.

• Automatic Rotation: Passwords expire and rotate automatically based on a defined policy.
• Centralized Control: Authorized admins can retrieve the unique password for a specific machine when needed.
• Elimination of PtH: Because every machine has a different password, a hash stolen from one machine is useless on another.

Removing Permanent Local Admin Rights (Least Privilege)

The most effective way to secure local admin accounts is to ensure they are rarely used. Users should never operate as local administrators for daily tasks. By removing these rights, you eliminate the initial "landing pad" for attackers to run credential-dumping tools.

Using Endpoint Privilege Management (EPM) for Just-in-Time Access

EPM solutions allow organizations to implement "just-in-time" elevation. Instead of having a permanent local admin account with a static password, users can request elevated privileges for specific applications or tasks. This reduces the window of opportunity for an attacker to find and exploit administrative sessions.

Network Segmentation and SMB Signing

Technical controls can further limit the effectiveness of shared credentials.

• Microsegmentation: Prevent workstations from communicating directly with each other over SMB (ports 139/445).
• SMB Signing: Enforce SMB signing to prevent relay attacks where an attacker intercepts a credential exchange and replays it to another system.

Common Challenges in Remediation

Moving to a unique-password model is technically simple but operationally demanding for large enterprises.

Managing Non-Domain Joined and Legacy Systems

LAPS traditionally requires a connection to Active Directory. For remote workers, cloud-only systems, or legacy industrial control systems, implementing unique passwords requires alternative strategies. Organizations often turn to Privileged Access Management (PAM) vaults or cloud-native LAPS implementations to address these gaps.

Operational Friction for Help Desk Teams

The primary reason shared credentials exist is convenience. If a technician needs to fix twenty computers, they want one password. Moving to unique credentials requires the help desk to use a retrieval tool for every single session. Success requires integrating password retrieval into existing ticketing and remote management workflows to ensure security doesn't stall productivity.

Detecting Shared Credential Abuse

While prevention is the goal, detection is a vital safety net. Organizations must monitor for the "smell" of lateral movement.

Monitoring for Anomalous SMB and WMI Activity

Security teams should alert on "workstation-to-workstation" traffic. In a healthy network, workstations communicate with servers, but they rarely need to communicate with each other over administrative ports. Sudden spikes in SMB or WMI connections between endpoints are a classic indicator of an attacker using shared credentials to scan or move through the environment.

Leveraging EDR/XDR for Credential Dumping Detection

Modern security platforms can detect the specific behaviors associated with credential theft.

• LSASS Protection: Alert when unauthorized processes attempt to read the memory of the LSASS process.
• Tool Execution: Monitor for the presence of tools like Mimikatz, BloodHound, or specialized PowerShell scripts used for credential harvesting.

Shared Local Admin Credentials FAQs