How can security teams detect Direct Volume Access?

How Direct Volume Access shows up in practice

direct volume access is most visible when a process talks to storage at the raw volume or disk layer instead of through ordinary file operations. That pattern often stands out because it is unusual for everyday applications, yet common for administration, backup, imaging, forensics, and some security tools. The key question is not just “who opened the disk?”, but whether that access matches an approved operational purpose.

Detection works best when teams compare volume-level activity with process reputation, account context, and timing. A legitimate backup agent or disk utility should be predictable, while an unknown binary opening a raw disk, reading MBR or partition data, or touching a volume outside its normal job is a stronger signal. If the process appears alongside credential theft, tampering, or security-tool interference, the finding deserves faster triage.

One useful angle is to baseline which hosts are expected to perform raw-volume operations. Servers used for backup, EDR, endpoint imaging, or storage administration may legitimately do this, but the same behaviour on a user workstation, jump box, or lightly managed system is more suspicious. Review parent process chains, command-line arguments, code signing, and the service account or privileged token used to launch the process.

Why raw-disk access is a security signal

Raw volume access matters because it can bypass file-level monitoring and interact directly with data structures that normal applications never need. That makes it attractive for backup and recovery, but also for attackers who want to read files without triggering normal application controls, tamper with data structures, or stage destructive actions. The behaviour can therefore indicate either a legitimate high-trust tool or a compromise path that deserves confirmation.

When teams investigate, they should look for evidence that the access pattern is proportional to the tool’s role. A trusted backup product with stable behaviour is different from an unsigned executable, a renamed admin tool, or a process running from a user-writable path. Where direct disk access is not expected, the absence of a clear business justification is itself a detection clue.

Monitoring should also include adjacent signals such as unusual privilege elevation, remote execution, disabled security tooling, or sudden access to sensitive storage shortly before exfiltration. Direct volume access rarely exists alone; it often appears as part of a broader sequence that includes staging, hiding, or extracting data. For a broader view of how storage-heavy tooling can be abused or defended, see the EDR Evasion and Defence Guide, which covers tampering and sensor-blinding techniques that often accompany suspicious low-level access.

Detection workflow and control points

Security teams should focus first on telemetry that can actually observe raw disk or volume interaction. That includes endpoint process telemetry, driver loading events, administrative command usage, and storage-related system events where available. If EDR or system logging does not expose the full access path, compensate by correlating process creation, privileged logons, and storage administration activity so you can distinguish approved maintenance from suspicious access.

Restrict who can open raw volumes, and make exceptions explicit. Approved backup systems, forensic utilities, and storage administrators should run from known hosts and known service identities, not from ad hoc administrator sessions. A control is more effective when it pairs permissions with allowlisted tooling and change-managed use cases, rather than relying on a generic admin role alone.

Detection also improves when teams compare direct-volume activity against the normal file API pattern on the same endpoint. A process that never needs direct storage access but suddenly starts using it is worth investigating even if no alert fired. If you already track privileged remote access pathways, the Remote Access Identity Guide is useful for understanding how administrative access paths should be bounded before they can be used for storage operations.

Risk and Threat Considerations

Direct Volume Access becomes risky when it is available to more accounts, hosts, or binaries than the business actually needs. The main exposure is not the raw access itself, but the combination of low-level storage reach, elevated privilege, and weak attribution, which can let a legitimate-looking tool read or alter data outside normal file controls.

Failure mechanism: An attacker or rogue tool gains administrative execution, then uses raw disk or volume access to bypass application-layer visibility, extract data, tamper with storage structures, or prepare destructive activity while blending in with maintenance workflows.

Impact: Teams may miss early signs of compromise, lose confidence in the integrity of stored data, or discover the activity only after credential abuse, exfiltration, or recovery failures have already occurred.

Practitioner Guidance

What to verify: Confirm which hosts, accounts, and binaries are genuinely authorized to open raw volumes, and verify that each one has a clear operational owner. If the access path is not tied to backup, imaging, recovery, or storage administration, treat it as suspicious rather than merely unusual.

Decision rule: If the process is unknown, unsigned, or launched from a user context, investigate it as potential compromise even when the host has administrative users. If the activity belongs to a known tool, validate whether the timing, target volume, and initiating account match the approved maintenance window.

Common mistake: Teams often focus on the presence of an admin account and miss the more important question of whether the specific binary and endpoint are allowed to use raw storage access. That shortcut weakens detection because Direct Volume Access can be perfectly valid in one environment and highly suspicious in another.

Practitioner takeaway: The best signal is not raw-volume access by itself, but raw-volume access that is unexpected for the process, host, or account and is not explained by a tightly controlled operational use case.

Related resources from NHI Mgmt Group

• Why are NHIs a critical concern for security teams?
• What steps should security teams take to prevent Shadow AI risks?
• Why is the abuse of NHIs a priority for security teams?
• What is the difference between SAST and DAST for security teams?