Why do multifunction printers increase domain compromise risk?

Because they are often trusted to authenticate to email, file shares, and directory services on behalf of the business. If those credentials are over-privileged or never rotated, compromise of the printer can provide a valid domain account that supports lateral movement and escalation.

Why Multifunction Printers Become Domain-Trust Risks

Multifunction printers are not just peripherals. In many estates they sit at the intersection of print, scan-to-email, file transfer, and directory services, which means they often hold credentials that can reach far beyond the device itself. That makes them a practical domain compromise path when local admin access, firmware weakness, or exposed management interfaces let an attacker extract secrets or alter device behavior. NHIMG’s 52 NHI Breaches Analysis shows how often non-human identities become the weak link once they are treated as utility accounts instead of governed identities.

The main security mistake is assuming a printer account is low value because users rarely log in to it directly. In reality, these devices may authenticate to Active Directory, SMTP, SMB shares, LDAP, and sometimes cloud connectors, so one compromised device can expose a chain of trusted services. That is why the relevant issue is not the printer hardware itself, but the standing access attached to it. Current guidance from NIST Cybersecurity Framework 2.0 is to identify and govern assets that can affect enterprise trust, including embedded systems. In practice, many security teams discover this only after a printer account is reused for lateral movement rather than during an intentional identity review.

How Compromise Moves from the Device to the Domain

A printer becomes dangerous when it can authenticate as something more trusted than itself. The common pattern is a device account configured once for convenience, then reused for years to support scan workflows, address books, or file drops. If that account has directory read access, mailbox permissions, or write access to shared folders, the printer becomes an access broker. Attackers do not need to “own the print job”; they need the credential material or the trust relationship behind it.

The operational path usually looks like this: gain administrative access to the device, extract stored secrets, intercept network traffic, abuse weak update paths, or pivot through exposed web consoles. Once inside, the attacker looks for:

• LDAP bind credentials used for address book lookup or authentication
• SMTP credentials used for scan-to-email delivery
• SMB or file-share credentials used for scan-to-folder workflows
• Management APIs or SNMP communities that reveal configuration data
• Cached tokens, certificates, or service account passwords stored on the appliance

NHIMG’s Ultimate Guide to NHI Security Matters Now explains why this class of trust relationship is treated as an identity problem, not just a device problem. The control objective is to reduce standing privilege, constrain where the account can authenticate, and rotate any credential the device depends on. For implementation detail, the device should be managed like any other workload identity with the smallest possible permission set, rather than as a permanently trusted shared account. These controls tend to break down in flat networks with legacy print servers because the printer can reach too many internal services and the account is reused across multiple workflows.

What Good Governance Looks Like in Legacy Print Environments

Tighter printer governance often increases operational overhead, requiring organisations to balance service continuity against credential isolation. That tradeoff is especially real in older environments where firmware is limited, vendor support is weak, and scanning workflows were built around shared credentials. Best practice is evolving, but the direction is clear: eliminate static secrets where possible, rotate service credentials on a defined schedule, and block printer accounts from broad directory or file-share access unless a business case is documented.

Two practical guardrails matter most. First, isolate printer identity from human identity and from other devices, so compromise of one MFP does not reveal reusable access elsewhere. Second, treat management-plane exposure as a risk surface: lock down admin interfaces, restrict outbound destinations, and log authentication to directory services so unusual printer behavior is visible. The Top 10 NHI Issues resource and the Anthropic AI-orchestrated cyber espionage report both reinforce the same lesson: when an automated system can act on its own, the security boundary must be the identity and the permitted action, not the box it runs on. In older print estates, the guidance tends to fail when legacy scan-to-folder integrations cannot support rotation or scoped permissions without disrupting business users.

Related resources from NHI Mgmt Group

• Why do domain controllers with NTLMv1 enabled increase domain compromise risk?
• Why do Backup Operators privileges increase domain compromise risk?
• Why do credentialed footholds increase the risk of rapid domain compromise?
• Why do standing owner roles increase risk in smart contract operations?