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Protection from Malicious Software: Malware protection on clinical endpoints

February 9, 2026 · Ken Armstrong

45 CFR 164.308(a)(5)(ii)(B) is the requirement on protection from malicious software. It is short to read and easy to underestimate, because satisfying it means producing evidence rather than holding an intention.

What the rule says

Protection from malicious software (Addressable). Procedures for guarding against, detecting, and reporting malicious software.

That is the text of 45 CFR 164.308(a)(5)(ii)(B). Read it closely: it describes an outcome to achieve, not a product to buy, which is why two practices of the same size can satisfy it in different ways and both be right.

This is an addressable implementation specification, and addressable does not mean optional. Under 45 CFR 164.306(d)(3) you assess whether the specification is reasonable and appropriate in your environment, and then either implement it or, if implementing it is not reasonable and appropriate, document why and implement an equivalent alternative measure if that is reasonable and appropriate. The documented reasoning is itself part of the requirement, so an undocumented decision to skip it is the finding.

What this looks like in practice

In an assessment, 45 CFR 164.308(a)(5)(ii)(B) is not one question. It resolves into several, and each one is really asking for different evidence. These are among the questions asked about it:

  • Does the organization document its policies and procedures for protection from malicious software (§ 164.308(a)(5)(ii)(B)) and review them periodically and update them as needed in response to environmental or operational changes affecting the security of ePHI?
  • Does the organization deploy anti-malware protection on systems that handle sensitive data and ensure its detection signatures and engine are automatically kept current?
  • Does the organization control the installation of software on operational systems that handle ePHI?

Ownership usually sits with the security official, though the evidence is often produced by someone else, which is where the trail breaks. A control that works but has no owner tends to stop working the month the person who quietly maintained it changes roles.

Who this applies to

Every covered entity and every business associate, at any size. 45 CFR 164.306(b) allows flexibility of approach, so a two-provider practice and a hospital system may implement this differently and both comply. What flexibility does not allow is skipping the decision: the smaller the organization, the more the written reasoning carries the weight, because there is no scale of operation to make the control self-evident.

Building it, in order

These steps are one way to meet it, drawn from our question bank. Unless a step names a provision, the Security Rule does not require that particular measure: 45 CFR 164.306(b)(1) lets you use any security measures that allow you to reasonably and appropriately implement the standards and implementation specifications, chosen with the factors in 45 CFR 164.306(b)(2).

The sequence below is the order that produces evidence as a by-product rather than as a separate documentation exercise:

  1. Document policies and procedures for guarding against, detecting and reporting malicious software.
  2. Document the supporting procedures that put them into practice.
  3. Assign an owner, review the documents periodically, and update them as needed in response to environmental or operational changes affecting the security of ePHI.
  4. Communicate the documents to the workforce members they apply to, for example with management's approval recorded.
  5. Deploy anti-malware software on all servers, workstations, and endpoints that access or store sensitive data.
  6. Configure detection signatures and engine files to update automatically as the vendor releases them and push those updates to every client.

Where else this maps

The questions behind 45 CFR 164.308(a)(5)(ii)(B) also map to HHS 405(d) HICP (2023 Edition) CSP 1, CSP 2 and NIST SP 800-66 Rev. 2 5.5.1, 5.5.2, which are voluntary guidance rather than law; following them does not by itself establish compliance with any law. That matters for scoping: the same evidence can be written once and referenced from each, rather than rewritten per framework.

Evidence an assessor asks for

For this requirement the evidence types that satisfy it are configuration, policy, and procedure. The distinction matters more than it looks: a policy states what you intend to do, a procedure states how, and a record proves it happened on a date. Auditors ask for all three, and a practice that has written the first two often has nothing for the third.

Date every document and keep the superseded versions. 45 CFR 164.316(b)(2)(i) requires the documentation 164.316(b)(1) calls for (the Security Rule policies and procedures, and the written record of any action, activity or assessment the Security Rule requires to be documented) to be retained for six years from the date of its creation or the date when it last was in effect, whichever is later, so a policy you replaced two years ago is still part of the record.

Where this usually goes wrong

The most common failure here is treating addressable as optional. A practice decides the specification does not fit, implements nothing, and writes nothing down. At assessment the answer to "why not" is a verbal explanation, which is not evidence. The second most common failure is the opposite: implementing an alternative that works, and still not recording the reasoning, so the control looks accidental.

What to do about it

  • Produce the evidence, not the intention. For 45 CFR 164.308(a)(5)(ii)(B) that means a configuration export or screenshot showing the setting live, dated, a signed, dated policy with a named owner and a review date, and a step-by-step procedure someone unfamiliar with the task could follow. If the only evidence is that someone knows how this works, you have a practice and not a record.
  • Put a name on it. Your security official should be recorded as the owner. Where the work is done by someone else, say so in the document: the split between who owns it and who performs it is where the trail usually breaks. A control with no owner stops working the month the person who quietly maintained it changes roles, and nobody notices.
  • Re-read it when something changes. A new system, a new vendor or a departure is what makes a correct control stale. Tie the review to those events as well as to the calendar, and date the result.
  • If you decide not to implement it, write the decision down. Addressable is not optional: under 45 CFR 164.306(d)(3) the documented assessment IS part of the requirement, so an undocumented decision to skip it is the finding, and a working alternative with no recorded reasoning looks accidental.

The recurring lesson with protection from malicious software is that documentation is not the paperwork after the control. It is the part an assessor can read, and therefore the part that has to exist.

Related requirements

References

  • 45 CFR 164.308(a)(5)(ii)(B), in 45 CFR 164.308 on eCFR. Quoted text verified against the eCFR text current as of 2026-10-06.
  • The Required and Addressable designations are defined at 45 CFR 164.306(d).
  • Crosswalk references in this post are the mappings in our question bank, and are not verified against the published text of those standards.
  • This post describes what a requirement asks for and what evidence documents it. It is not legal advice, and your counsel owns the conclusion. State law may impose additional obligations; HIPAA preempts a State law only where it is contrary to HIPAA (45 CFR 160.202, 160.203).