CIS Controls v8.1 IG1 Ransomware-Resilience Sprint: A 30-60-90 Day Action Plan (With Evidence Checklist)

At 2:17 a.m., you’re staring at a ransom note you didn’t plan for. The file share is renamed. The phone starts ringing. Someone asks the question that turns your stomach: “Do we have clean backups—and can we prove it?”

In that moment, ransomware resilience isn’t a “framework project.” It’s a short list of controls you either operationalized or you didn’t.

This article turns CIS Controls v8.1 IG1 into a practical 30–60–90 day ransomware-resilience sprint, with an evidence checklist you can hand to leadership, auditors, and insurance questionnaires.

What you’ll learn

• What CIS Controls v8.1 IG1 is (and why it’s a strong ransomware baseline)
• A 30–60–90 day action plan mapped to high-leverage CIS Controls
• The minimum evidence you should collect as you implement (so progress is provable)
• Where teams commonly stall (scope creep, tooling, and governance friction)
• How to set up metrics that support continuous improvement—not checkbox security

Table of contents

• CIS Controls v8.1 IG1: What it is and why it maps well to ransomware resilience
• Day 0–30: Get visibility fast (Controls 1–2 and baseline logging)
• Day 31–60: Break common ransomware paths (MFA, hardening, vulnerabilities, email/web)
• Day 61–90: Prove recovery and response (backups, monitoring, IR readiness)
• Evidence checklist: What “done” looks like for an IG1 sprint
• The Counter-Intuitive Lesson I Learned
• FAQ

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CIS Controls v8.1 IG1: What it is and why it maps well to ransomware resilience

Answer-first: CIS Controls v8.1 is a prescriptive cybersecurity framework with 18 Controls and 153 Safeguards. Implementation Group 1 (IG1) contains 56 essential Safeguards intended as “minimum viable cyber hygiene” for most organizations, and it aligns well to ransomware resilience because it prioritizes visibility, access control, secure configuration, and recovery fundamentals.

If you implement IG1 with evidence, you’re building the conditions that make ransomware harder to deploy—and easier to contain and recover from.

Elaboration (how to think about IG1 for ransomware)

Ransomware doesn’t win because attackers are “magic.” It wins because defenders lack one (or more) of these basics:

• You don’t know what you own (unknown endpoints, unknown SaaS, unknown servers)
• You can’t enforce secure defaults (misconfigurations and drift)
• Credentials are easy to steal and reuse (weak admin protections, missing MFA)
• Patching is inconsistent (known exploits stay open)
• Logging is missing or unused (you learn about the incident too late)
• Recovery is unproven (backups exist, but restores fail)

IG1 is designed to start with that reality, not fight it.

Also, CIS deliberately supports multi-framework environments: CIS has published a CIS Controls v8 to NIST CSF 2.0 mapping so you can connect day-to-day safeguards to governance and risk reporting without reinventing crosswalk spreadsheets.

Evidence (from approved CIS material)

• CIS Controls v8/v8.1 includes 18 Controls and 153 Safeguards, organized into IG1–IG3.
• IG1 contains 56 Safeguards designed as essential cyber hygiene.
• CIS provides a mapping white paper from CIS Controls v8 to NIST CSF 2.0, including alignment to the CSF’s updated structure (including the Govern function).

Key takeaway: Treat IG1 as a ransomware resilience baseline—not a compliance trophy. Your goal is fast visibility, fewer credential paths, and provable recovery.

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Day 0–30: Get visibility fast (Controls 1–2 and baseline logging)

Answer-first: In the first 30 days, your objective is simple: reduce unknowns. That means an automated enterprise asset inventory (Control 1), an automated software inventory (Control 2), and enough centralized logging (Control 8) to investigate suspicious activity quickly.

Ransomware response fails most often when inventory and logs are incomplete.

Step-by-step sprint plan (first month)

1) Build an “authoritative” asset inventory (Control 1)

Aim for a living system, not a spreadsheet.

• Active discovery: run routine network scans to identify connected assets.
• DHCP logging to inventory/CMDB: ensure dynamic endpoints still get captured.
• Passive discovery: observe network traffic to identify unmanaged/ephemeral devices.
• Define a basic process for unauthorized assets: tag → owner lookup → isolate/quarantine.

2) Build a software inventory that supports allowlisting later (Control 2)

Start with “what’s installed where,” then evolve toward “what is allowed to execute.”

• Capture software name, version, publisher, and install date where feasible.
• Identify “high-risk” categories early: remote admin tools, scripting runtimes, file sharing apps.
• Flag unsupported or end-of-life software for remediation planning.

3) Turn on baseline centralized logging (Control 8)

Month 1 is not about perfect SIEM content. It’s about not being blind.

Minimum log sources to centralize:

• Identity provider / directory authentication events
• Endpoint security (anti-malware/EDR) alerts
• Firewall / VPN logs for remote access visibility
• Key server logs for file shares and admin activity (where available)

Mini-checklist (Day 0–30 exit criteria):

• One inventory for enterprise assets with automated updates
• One inventory for installed software (at least endpoints + servers)
• A documented “unknown device” workflow (tag, investigate, isolate)
• Central log collection for identity + endpoints + remote access

Evidence (from approved CIS material)

• CIS Control 1 includes safeguards for active discovery, DHCP logging, and passive discovery to keep inventories current in dynamic environments.
• CIS Control 2 includes safeguards for automated software discovery and (later) application allowlisting and script controls.

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Day 31–60: Break common ransomware paths (MFA, hardening, vulnerabilities, email/web)

Answer-first: Days 31–60 are about shutting down common ransomware entry and escalation routes: enforce secure configuration (Control 4), harden identities and admin access (Controls 5–6), run continuous vulnerability management (Control 7), and reduce phishing/web delivery risk (Control 9) while strengthening malware defenses (Control 10).

This is where “good hygiene” becomes “hard to compromise.”

Step-by-step sprint plan (month two)

1) Apply secure configuration baselines (Control 4)

Don’t hand-write baselines from scratch. Use CIS resources where possible.

• Pick your highest-risk platforms (typical: Windows endpoints, Windows/Linux servers, Microsoft 365, core network devices, and key cloud accounts).
• Start with a “Level 1” style approach: changes that reduce attack surface without breaking operations.
• Create an exceptions process (documented owner, compensating control, review date).

Practical resource: CIS Benchmarks are freely downloadable at https://learn.cisecurity.org/benchmarks.

2) Make privileged access meaningfully harder to abuse (Controls 5–6)

Ransomware operators love admin access. Reduce that blast radius.

• Enforce MFA for all administrative access (Control 6.5).
• Enforce MFA for remote access (Control 6.4) and externally-exposed applications (Control 6.3). Ransomware often enters via RDP or exposed web apps.
• Ensure a process exists to revoke access immediately upon termination (Control 6.2).
• Reduce standing privileges where possible (move toward just-in-time patterns over time).

3) Stand up continuous vulnerability management (Control 7)

This is the engine that closes known exploit paths.

• Enable automated patch management for operating systems (Control 7.3) and applications (Control 7.4).
• Prioritize updates by asset criticality and exposure (internet-facing and identity systems first).
• Create remediation SLAs you can report on (even if they start rough).

4) Reduce phishing and web-based delivery (Control 9) and strengthen malware defenses (Control 10)

Keep it pragmatic:

• Block common risky attachment types and risky URL patterns (policy + tooling).
• Ensure anti-malware/EDR is centrally managed and updated.
• Validate that endpoints are actually reporting back (coverage matters more than purchasing).

Pro tip: Don’t let month two become a “tooling debate.” If you need a SIEM/EDR choice, pick what you can operate well. Open-source stacks can work—but only if you staff and tune them.

Evidence (from approved CIS material)

• CIS Control 6.5 explicitly calls for MFA for administrative access.
• CIS provides extensive CIS Benchmarks (free downloads) to accelerate Control 4 secure configuration.
• CIS emphasizes Control 7 as continuous and automation-friendly (not periodic checkbox scanning).

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Day 61–90: Prove recovery and response (backups, monitoring, IR readiness)

Answer-first: In days 61–90, your goal is proof: prove you can restore (Control 11), prove you can detect and investigate (Controls 8 and 13), and prove you can coordinate a response (Control 17).

Ransomware resilience is measured in restores, containment, and decision speed—not policies.

Step-by-step sprint plan (month three)

1) Make recovery real (Control 11)

Backups that haven’t been restored are hypotheses.

• Define “critical”: which systems must be restored first to keep the business alive.
• Confirm backup separation/segmentation so ransomware can’t trivially encrypt backups too.
• Run at least one restore test per critical system class (file share, identity-dependent app, database-backed app).
• Document RTO/RPO assumptions as “current best known,” then refine.

2) Expand monitoring where it reduces dwell time (Controls 8 and 13)

You don’t need every log. You need the right ones.

Prioritize detection coverage around:

• Authentication anomalies (admin logins, failed MFA, impossible travel patterns if available)
• Endpoint behavior consistent with encryption activity (mass file rename/write)
• Lateral movement signals (remote exec tools, admin shares, unusual SMB patterns)

Tooling patterns (choose one you can run):

• Open-source: Wazuh (SIEM + EDR capabilities), Security Onion (bundled Zeek/Suricata/Elastic), plus Elastic/OpenSearch/Graylog as log backbones.
• Commercial: platforms like Splunk Enterprise Security emphasize unified detection, investigation, and response, and support SOC KPIs such as MTTD/MTTR and false-positive reduction (as described in Splunk security positioning).

3) Operationalize incident response (Control 17)

IR is coordination under stress.

• Name roles (incident commander, IT lead, comms/legal liaison, vendor liaison).
• Create a ransomware playbook: isolate → preserve evidence → assess scope → restore → communicate.
• Run a tabletop exercise based on your environment (not a generic script).

Key takeaway: Your “90-day win” is a tested restore + a rehearsed response path + enough telemetry to investigate.

Evidence (from approved CIS material)

• CIS Control 11 focuses on data recovery capability (backup and restore discipline).
• CIS highlights platforms and approaches that support measurable SOC operations; Splunk materials emphasize SOC KPIs like mean time to respond (MTTR) and reducing alert fatigue through automation.

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Evidence checklist: What “done” looks like for an IG1 sprint

Answer-first: Evidence is how you turn an IG1 sprint into a defensible security claim. The best evidence is system-generated and reviewable: inventories, configurations, logs, tickets, screenshots, and test results tied to specific safeguards and dates.

If it can’t be shown, it will be questioned during an incident or audit.

Evidence artifacts to collect (practical minimum)

Controls 1–2: Inventory (the ransomware prerequisite)

• Asset inventory export (with last-seen timestamps)
• Proof of active discovery configuration and schedule
• DHCP log ingestion evidence (sample logs + linkage to inventory/CMDB)
• Passive discovery reports (weekly review notes)
• Software inventory export (with versions)
• Exception list for unauthorized software + remediation tickets

Control 3: Data protection (keep scope survivable)

• Data classification/inventory snapshot (even if partial—start with crown jewels)
• Encryption status evidence for endpoints/servers holding sensitive data
• Retention/disposal policy and an example of execution (ticket/change record)

Controls 4–7: Hardening, access, vulnerability management

• CIS Benchmark reference list (which benchmarks you adopted and where)
• Configuration compliance reports (or at least before/after hardening evidence)
• MFA enforcement evidence for admin access (policy + system screenshot/export)
• MFA enforcement evidence for remote access and external apps (Controls 6.3, 6.4)
• Employee termination tickets showing immediate access revocation (Control 6.2)
• Automated patch management logs/reports (Controls 7.3, 7.4)

Controls 8–10, 12–13: Logs, email/web, malware, network defense

• Log source list + retention settings + integrity protections where applicable
• Email/web filtering policy evidence (blocked types, URL protections, etc.)
• Endpoint protection coverage report (percent reporting, update status)
• Network monitoring placement notes (what segments, what alerts are triaged)

Control 11: Recovery

• Backup job success reports
• Restore test results (date, system, outcome, time to restore, issues found)

Control 17: Incident response

• IR plan/playbook
• Tabletop agenda + attendance + after-action notes

Mini-checklist (evidence hygiene):

• Every artifact has an owner and date
• Evidence is exportable (not “tribal knowledge”)
• Findings produce tickets, not just notes
• You can answer: “What changed in the last 30 days?”

Evidence (from approved CIS material)

• CIS provides automation and mapping support via the CIS Controls Navigator, which maps CIS Controls to 25+ standards (reducing manual crosswalk burden).
• CIS safeguards are written to be testable and measurable, enabling evidence-driven implementation.

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The Counter-Intuitive Lesson I Learned

Answer-first: The counter-intuitive lesson is that ransomware resilience often collapses not on malware tooling—but on governance of “small” third-party and data decisions. If you don’t treat third-party services, scripts, and data retention as first-class assets, you create silent scope and risk that IG1 controls can’t compensate for.

In other words: your most dangerous “unknown” might be business-as-usual.

Elaboration (why this keeps surprising teams)

I didn’t learn this from a single dramatic war story I can share publicly. I learned it from patterns embedded in CIS guidance and from how modern environments actually work.

A surprisingly concrete example is CIS’s own public cookie disclosures (a real-world snapshot of third-party complexity):

• 35 Necessary cookies (security and core functionality)
• 50 Statistics cookies (analytics/measurement)
• 94 Marketing cookies (cross-site targeting)
• Some cookie durations extend up to 30 years (for example, a Matomo consent cookie), and marketing cookies can run hundreds of days

That isn’t “bad.” It’s realistic. It’s also a governance signal: third-party sprawl and long retention windows create data protection and supplier-management obligations that must be handled deliberately.

For your ransomware-resilience sprint, the implication is practical:

• Include third-party services (SaaS, scripts, integrations, vendors) in Controls 1–2 inventories
• Treat data collection and retention as part of Control 3
• Use Control 15 (Service Provider Management) thinking even if you’re “only” doing IG1: inventory providers, define owners, and review risk

Key takeaway: IG1 succeeds faster when you reduce “organizational unknowns,” not just technical unknowns.

Evidence (from approved CIS material)

• CIS’s cookie categorization disclosure shows 35 Necessary / 50 Statistics / 94 Marketing cookies and highlights long-lived retention (up to 30 years)—a concrete illustration of vendor and data-governance complexity.
• CIS v8/v8.1 strengthens emphasis on Data Protection (Control 3) and Service Provider Management (Control 15) to reflect modern outsourced/cloud ecosystems.

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FAQ

1) Is IG1 “enough” for ransomware resilience?

IG1 is a strong baseline, especially against common ransomware paths, but it’s not a guarantee. Use IG1 to establish minimum hygiene, then extend toward IG2 as your environment and risk demand.

2) What’s the fastest IG1 win in the first two weeks?

Asset visibility (Controls 1–2) plus MFA for admin access planning (Control 6.5). You can’t patch, monitor, or contain what you can’t see.

3) Do I need a full SIEM in 30 days?

Not necessarily. You need centralized logging for key sources (identity, endpoints, remote access). Mature SIEM use cases can follow once ingestion and ownership are stable.

4) Open-source vs. commercial monitoring—what’s better?

Open-source (Wazuh, Security Onion, Elastic/OpenSearch/Graylog) can be effective but requires tuning and operational discipline. Commercial platforms (for example, Splunk Enterprise Security) can accelerate workflows and KPI reporting—if budget allows.

5) How do I avoid scope creep with CIS Controls?

Pick your target IG (IG1) and timebox the sprint. CIS explicitly warns that trying to implement all 153 Safeguards at once is a common failure pattern; IGs exist to prevent that.

6) What evidence do executives care about most?

Restore tests (Control 11), MFA coverage for admin access (Control 6), vulnerability remediation trends (Control 7), and visibility coverage (Controls 1–2). Concrete artifacts beat status slides.

7) Where does NIST CSF 2.0 fit if we’re using CIS?

Use CIS as the implementation layer and leverage CIS’s v8 to NIST CSF 2.0 mapping to report progress in CSF terms (including Govern) without duplicating effort.

Key Terms (mini-glossary)

• CIS Controls v8.1: A prescriptive framework of 18 Controls and 153 Safeguards from the Center for Internet Security.
• Implementation Group (IG): CIS prioritization tiers (IG1–IG3) based on organizational capability and risk.
• IG1: The essential baseline consisting of 56 Safeguards.
• Safeguard: A specific, testable action under a CIS Control.
• CIS Benchmarks: Secure configuration guides for OS, cloud, apps, and databases (free downloads available).
• Active discovery: Scanning-based identification of network-connected assets.
• Passive discovery: Traffic/log-based identification of assets without active scanning.
• MFA: Multi-factor authentication; strongly recommended for privileged/admin access.
• RBAC: Role-based access control; access is assigned by role rather than ad hoc permissions.
• SIEM: Security information and event management; centralizes logs for detection and investigation.
• MTTD/MTTR: Mean time to detect / mean time to respond—common SOC effectiveness metrics.

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The next time it’s 2:17 a.m., the best outcome isn’t “we bought a new tool.” It’s hearing your team say: “We know what’s affected. Admin access is locked down. Logs are coming in. Backups are clean. Restores are already in progress.”

That’s what an IG1 ransomware-resilience sprint is meant to deliver in 90 days: fewer unknowns, fewer easy paths, and recovery you can prove.

If you want help turning this into a scoped, evidence-driven implementation plan your team can execute, Gradum.io can support you with sprint planning, control mapping, and an audit-ready evidence pack.