DSS05: Managed Security Services

To meet the dss05: managed security services requirement, you must define, run, and evidence a repeatable security operations capability (in-house and/or through third parties) that detects, responds to, and reports on security events across your environment. Operationalize DSS05 by assigning ownership, documenting procedures, setting measurable service expectations, and retaining proof that monitoring and response happen consistently ¹.

Key takeaways:

• DSS05 is an operations control: auditors will look for day-to-day execution evidence, not slideware ².
• Treat managed security services as a governed service with scope, SLAs, escalation, and oversight, even if delivered by an MSSP ³.
• Your fastest path to exam readiness is a DSS05 evidence pack mapped to control ownership, procedures, and recurring artifacts ¹.

DSS05 in COBIT 2019 is where “security” stops being a strategy document and becomes an operational service that can be tested on demand. A CCO or GRC lead usually gets pulled into DSS05 for one of three reasons: a SOC or MSSP onboarding, an audit finding that “monitoring exists but isn’t provable,” or an incident that exposed unclear roles and weak escalation. DSS05 addresses those failure modes by requiring managed security services with defined responsibilities, procedures, and evidence of performance ¹.

This requirement page focuses on what you need to stand up quickly: clear service scope, ownership, playbooks, logging/alerting coverage, triage and escalation rules, and governance over any third party performing security operations. The operational goal is simple: if an examiner asks “show me how you detect and respond to security events,” your team can produce artifacts that trace from policy to tickets to outcomes without heroics. A practical way to get there is to create a DSS05 control map and evidence binder aligned to your actual tooling and operating model ².

Regulatory text

Provided excerpt (framework summary): “COBIT 2019 objective DSS05 implementation expectation.” ¹

What this means for an operator (plain English): DSS05 expects you to operate security as a managed service: defined scope, named owners, documented procedures, and recurring execution evidence. If you outsource any portion (SOC monitoring, incident response retainer, MDR/MSSP), you still own governance: you must define expectations, oversee performance, and retain proof the service works in practice ¹.

Plain-English interpretation (what DSS05 is really asking)

DSS05 is satisfied when you can demonstrate all of the following, end-to-end:

1. Coverage: you know what systems, networks, and logs are in scope for security monitoring and response.
2. Operations: alerts are reviewed, investigated, escalated, and closed using documented procedures.
3. Accountability: there is a clear chain of command for decisions (containment, eradication, notification).
4. Oversight: management reviews security service performance and makes improvements based on findings.
5. Evidence: you can prove the above happened over time, not just “we have a tool” ².

This is why the recommended control in your data pack is so practical: document control ownership, procedures, and evidence mapped to DSS05 ¹.

Who it applies to

Entity scope

• Enterprise IT organizations implementing COBIT 2019, including regulated firms that use COBIT to structure IT governance and control programs ².

Operational context (where DSS05 shows up)

DSS05 applies anywhere you provide or consume security operations capabilities, including:

• Internal SOC / security operations team
• Hybrid models (internal triage plus external MDR/MSSP)
• Fully outsourced monitoring and response (MSSP-led), where your obligations shift to oversight and integration but do not disappear ³.

What you actually need to do (step-by-step)

Use this sequence to operationalize DSS05 quickly and defensibly.

Step 1: Declare the “Managed Security Service” and its boundaries

Create a one-page DSS05 Service Definition:

• In-scope environments (cloud accounts, endpoints, identity provider, core apps, network)
• In-scope event sources (EDR, SIEM logs, cloud audit logs, email security, IAM events)
• In-scope hours of coverage and handoffs (business hours vs 24x7)
• Out-of-scope explicitly listed (shadow IT, unmanaged endpoints, acquired entities)

Operator tip: auditors tolerate partial coverage if it is documented, risk-accepted, and has a plan. They do not tolerate “we think we cover everything.”

Step 2: Assign control ownership and RACI that matches reality

Minimum roles to document:

• Control owner (DSS05 owner): accountable for design and evidence
• Service owner (SOC/MSSP relationship owner): accountable for daily performance
• Incident commander: accountable for major incident decisions
• Evidence steward: responsible for collecting artifacts for audit

If a third party performs monitoring, document who approves rule changes, who can declare an incident, and who talks to legal/compliance.

Step 3: Write procedures that map to the workflow you run

Keep procedures short and testable. Cover:

• Alert intake and triage criteria (severity definition)
• Investigation steps (enrichment sources, correlation expectations)
• Escalation path and timelines (internal escalation, third party escalation)
• Containment actions and approvals (endpoint isolation, account disablement)
• Case closure requirements (root cause notes, lessons learned, ticket hygiene)
• Communication triggers (who gets notified; what requires compliance involvement)

Step 4: Instrument detection and logging with an explicit coverage map

Create a Logging & Detection Coverage Matrix:

• Asset category → telemetry source → retention owner → monitoring owner → gaps/compensating controls

This becomes your “control operating model” exhibit. If you run an MSSP, require them to confirm onboarding status per log source and provide onboarding evidence.

Step 5: Contract and oversee third parties as part of the control

For managed security service third parties, implement governance that produces evidence:

• Scope of service and responsibilities
• SLAs/SLOs that reflect your risk (triage, escalation, reporting)
• Data handling and access controls (how they access your environment)
• Reporting package (monthly service report, notable incidents, tuning changes)
• Issue management (how findings become remediations and who tracks them)

Practical standard: treat the MSSP like any other critical third party, but with higher scrutiny on detection coverage, escalation, and evidence quality.

Step 6: Create a repeatable evidence cadence (this is where teams fail)

Define an “evidence calendar” for DSS05:

• Operational evidence: alert/case tickets, escalations, incident records
• Oversight evidence: service review minutes, KPI/KRI reports, action items
• Improvement evidence: tuning logs, detection rule change records, post-incident reviews

If you want this to run without manual chasing, Daydream is typically introduced here: it helps structure third-party oversight requests and maintain an audit-ready evidence trail tied to DSS05 control ownership and procedures, instead of relying on inbox archaeology ¹.

Required evidence and artifacts to retain

Build a DSS05 evidence pack with “show me” artifacts an auditor can sample:

Governance and design artifacts

• DSS05 control statement and ownership
• RACI for SOC/MSSP + internal stakeholders
• Managed Security Service Definition (scope, boundaries)
• Logging & Detection Coverage Matrix
• Incident response procedures and escalation runbooks

Operating evidence (sample-friendly)

• Alert queue exports or screenshots with timestamps and dispositions
• Case/ticket samples showing triage → investigation → escalation → closure
• Incident records for material events (timeline, decisions, approvals, comms)
• Detection tuning/change records (what changed, why, who approved)
• Monthly/quarterly service review materials with action items

Third-party oversight artifacts (if applicable)

• Contract/SOW sections covering monitoring, escalation, reporting
• MSSP onboarding confirmations and coverage attestations
• Service performance reports and remediation follow-ups

Common exam/audit questions and hangups

Auditors and examiners tend to probe these fault lines:

1. “Show me coverage.” They will ask which systems feed the SIEM/MDR and which do not, then test whether gaps are tracked.
2. “Who is accountable at 2 a.m.?” They will test escalation clarity: named roles, paging paths, decision authority.
3. “Prove it operates.” They will pick a week/month and request tickets, triage notes, and closures.
4. “How do you oversee the MSSP?” They will ask for service reviews, KPI reporting, and how you validate the MSSP’s claims.
5. “How do you improve?” They will look for evidence that incidents and trends lead to tuning and remediation ².

Frequent implementation mistakes (and how to avoid them)

Mistake	Why it fails DSS05	Fix
Buying MDR/SIEM and calling it “done”	Tools don’t equal managed services; no proof of triage/response	Require ticketing workflow, runbooks, and sampling-ready artifacts
No explicit scope	You cannot defend gaps or demonstrate coverage	Publish a service definition and coverage matrix
MSSP runs the show with little oversight	Accountability remains with you	Add governance cadence, acceptance criteria, and documented reviews
Incidents handled in chat only	No durable evidence trail	Route to an incident record with decisions and timestamps
Evidence collection happens only during audits	Missing artifacts and inconsistent sampling	Create an evidence calendar and automate collection where possible

Risk implications (what breaks when DSS05 is weak)

A weak DSS05 program tends to produce predictable outcomes:

• Missed detections because telemetry onboarding is incomplete or untracked
• Slow response because escalation paths and decision rights are unclear
• Regulatory exposure because you cannot prove operational control effectiveness
• Third-party concentration risk when a provider is “critical” but unmanaged ¹

Practical 30/60/90-day execution plan

Numeric timelines are guidance for organizing work, not a claim about how long implementation “should” take.

First 30 days (stabilize and define)

• Name DSS05 control owner and service owner; publish RACI.
• Draft the Managed Security Service Definition (scope + out-of-scope).
• Inventory log sources and build the first coverage matrix (even if incomplete).
• Standardize the ticketing workflow for alerts and investigations.
• Start an evidence folder structure tied to DSS05 (governance, operations, third party).

Days 31–60 (operationalize and evidence)

• Finalize core runbooks: triage, escalation, containment approvals, closure.
• Stand up a recurring service review (SOC + IT + compliance) and record minutes.
• If using an MSSP, align SOW/SLAs to your escalation and reporting needs; document any gaps and compensating controls.
• Run a tabletop that tests escalation and incident commander decisioning; record outcomes and action items.

Days 61–90 (prove repeatability and tighten oversight)

• Perform internal sampling: pick a period and verify ticket completeness end-to-end.
• Add detection tuning/change control (even lightweight) with approvals and logs.
• Close the largest coverage gaps and document risk acceptance for what remains.
• Produce a DSS05 “exam packet” with a control narrative and a curated set of artifacts that can be handed to audit without scramble ².

Frequently Asked Questions

Does DSS05 require a 24x7 SOC?

DSS05 requires managed security services appropriate to your environment and risk, with clear scope and evidence of operation ². If you do not operate 24x7, document coverage hours, after-hours escalation, and how you handle critical alerts.

If we outsource to an MSSP/MDR provider, are we compliant automatically?

No. Outsourcing can satisfy parts of DSS05, but you still need governance, defined expectations, and evidence that the third party performed monitoring and escalation as agreed ³.

What evidence is most persuasive to auditors for DSS05?

Time-stamped alert and incident tickets that show triage, escalation, decisions, and closure are usually the fastest proof. Pair those with the service definition, coverage matrix, and documented service reviews ².

How do we handle systems that cannot send logs to the SIEM?

Put them explicitly in the coverage matrix as gaps, define compensating controls (host logs, EDR-only monitoring, manual review), and track remediation or risk acceptance through your governance process.

Who should own DSS05: Security, IT, or Compliance?

Security operations typically owns execution, while compliance/GRC should own control mapping, testing, and evidence readiness. Assign a single accountable control owner and document the RACI so escalation and approvals work under stress.

Where does Daydream fit in DSS05 implementation?

DSS05 fails most often on evidence and third-party oversight. Daydream is a practical fit when you need a repeatable way to collect MSSP reports, track control ownership, and keep an audit-ready DSS05 evidence pack without rebuilding it during each review ¹.

Footnotes

1. ISACA COBIT overview; OSA COBIT 2019 objective mapping

2. ISACA COBIT overview

3. OSA COBIT 2019 objective mapping