Authors: S.Choudhuri

Category: Self Published Research

Date: 5th Oct 2023

Overview

What happened: NotPetya began as a malware campaign targeting Ukrainian organizations via a compromised accounting software (M.E.Doc) update, then rapidly propagated across networks using EternalBlue and credential‑theft tools to infect multinational companies in Europe (shipping, logistics, manufacturing, law firms). Though initially targeted, it caused widespread destructive encryption/wiping and huge business disruption across the EU.

Impact (high level): Major global firms (e.g., Maersk, Merck) reported operational stoppages, lost revenue, production outages, and multi‑hundred‑million‑dollar remediation costs; EU supply chains and logistics were disrupted. Total global damage estimates exceeded $10 billion.

Sequence of Events

1. Compromised vendor update channel (supply‑chain initial vector).
2. Malware executed via signed/legitimate updater, installing wiper with ransomware‑like behavior.
3. Rapid lateral spread using SMB/EternalBlue and harvested credentials (PsExec, WMI).
4. Destructive payload rendered systems inoperable; mass outages across sectors.
5. Remediation: rebuild from clean backups, reimaging, investigation and service restoration.

Confirmed/Likely Root Causes

• Supply‑chain compromise delivering malicious update (trusted vendor software).
• Unpatched SMB vulnerability (EternalBlue) enabling rapid worm‑like propagation.
• Poor network segmentation and excessive trust between business units/partners.
• Inadequate application allowlisting and endpoint containment.
• Weak detection and slow, large‑scale remediation due to destructive nature.

Views on how this may have been prevented using open‑source tools

Prevention goals

• Prevent supply‑chain tampering and validate software provenance.
• Reduce exploit surface (patching and virtual isolation).
• Limit lateral spread with segmentation, allowlisting, and least‑privilege.
• Detect anomalous network and host behaviour early.
• Ensure rapid recovery via immutable/air‑gapped backups.

Recommended free/open source tools and purposes

• Supply‑chain integrity
  • Sigstore / Cosign (verify signed artifacts) — validate vendor updates and container/image signatures.
  • In‑toto — track and verify software build provenance (SBOM generation).

• Vulnerability management & patching
  • OpenVAS / Greenbone Community Edition — scan for SMB/EternalBlue vuln exposure.
  • Ansible — automate emergency patching and configuration changes.

• Network segmentation & perimeter controls
  • pfSense / OPNsense — enforce micro‑segmentation, restrict SMB exposure, VPN gating.
  • iptables/nftables / Calico (K8s) — host‑level network policies to block lateral SMB traffic.

• Endpoint hardening & allowlisting
  • OSQuery + FleetDM — inventory and detect unexpected executables/changes.
  • AppArmor / SELinux (built‑in) + signed‑code allowlisting (simple policy enforcement) — prevent execution of unknown updater binaries.

• Detection & hunting
  • Suricata + Zeek — detect SMB exploit attempts, lateral movement and suspicious service traffic.
  • Wazuh / OSSEC — host IDS, file integrity monitoring and alerts for tampering.
  • Velociraptor — endpoint telemetry and rapid collection for incident triage.

• Logging, correlation & IR
  • ELK/OpenSearch + TheHive/Cortex — centralise logs, automate containment playbooks and coordinate response.

• Backups & recovery
  • BorgBackup / Restic with immutable snapshots and offline retention; Rclone to shift snapshots to isolated storage — ensure reliable recovery from clean images.

How these tools work in tandem to stop each factor

1. Supply‑chain tampering: Cosign/Sigstore and in‑toto validate vendor update signatures and build provenance before executing updates.
2. Unpatched SMB/EternalBlue: OpenVAS identifies vulnerable systems; Ansible deploys critical patches rapidly.
3. Lateral spread: pfSense/host firewall rules block SMB across segments; AppArmor/allowlisting prevents untrusted executables from running.
4. Delayed detection: Suricata/Zeek detect exploit patterns; Wazuh raises host alerts enabling faster containment.
5. Recovery: Borg/Restic air‑gapped immutable backups enable rebuilds without paying ransom and reduce downtime.

Example deployment architecture

Ingest vendor updates through a controlled proxy that verifies signatures with Cosign/in‑toto. Conduct vulnerability scanning using OpenVAS and maintain an emergency playbook for patching SMB vulnerabilities (MS17‑010) via Ansible. Network security involves denying SMB across VLAN boundaries, enforcing least privilege, and blocking outgoing SMB traffic with pfSense except to approved patch servers. For endpoints, use OSQuery with FleetDM for inventory, and implement AppArmor profiles, execution policies, and Wazuh for host intrusion detection. Network security monitoring is achieved with Suricata and Zeek sensors feeding data into OpenSearch dashboards and TheHive alerts. Backups are handled with Borg/Restic, ensuring regular immutable snapshots are kept offline and tested for restoration.

Cost‑benefit analysis (EU incidence model, illustrative)

Notes & assumptions

• Scenario: large European company (e.g., logistics firm) affected with outages; modelling both an individual large firm and an extrapolated EU aggregate impact. Figures in EUR and illustrative—based on public remediation costs (Maersk reported ~$200–300M, other firms varied).
• Open‑source tools are assumed free; costs are staff/infra and operational (liberally estimated). Prevention reduces probability of infection via these vectors and reduces impact if infected. Conservative mitigation effectiveness used: 60–90% depending on control.

A) Costs to deploy & operate open‑source stack (per large enterprise, 3 years)

• Initial deployment: 8 FTE‑months @ €9,000/month = €72,000.
• Ongoing SecOps/DevOps: 3 FTEs @ €95,000/year each = €285,000/year → 3‑year = €855,000.
• Infrastructure (sensors, storage, backup capacity): €120,000/year → 3‑year = €360,000.
• Testing, audits, tabletop IR and vendor verification process: €120,000 one‑time.Total 3‑year cost ≈ €1,407,000.

B) Estimated loss from a NotPetya‑style hit (per large firm)

• Direct remediation, lost revenue, rebuilds: use conservative mid estimate €150,000,000 (Maersk/Merck scale).
• Supply‑chain downstream costs (partners, customers): €50,000,000.Total per‑firm cost ≈ €200,000,000.

C) Prevented/lowered impact with open‑source stack

• Controls reduce likelihood of successful supply‑chain execution and/or prevent rapid spread in‑network; assume conservative 70% reduction in total impact.
• Avoided cost per firm ≈ 0.7 × €200,000,000 = €140,000,000.

D) Net savings per firm (3‑year)

• Avoided (€140,000,000) − Cost (€1,407,000) ≈ €138,593,000 saved.

E) ROI per firm

• ROI ≈ (€138,593,000) / €1,407,000 ≈ 9,855% over 3 years.

F) EU‑wide perspective (aggregate)

• NotPetya‑style cross‑EU systemic shock affected dozens/hundreds of firms; assume 100 large/medium firms suffer similar (conservative).
• Aggregate direct losses (modeled) ≈ 100 × €200,000,000 = €20,000,000,000.
• Aggregate avoided (70% mitigation) ≈ €14,000,000,000.
• Aggregate deployment cost (100 firms) ≈ 100 × €1,407,000 = €140,700,000.
• Net EU savings ≈ €13,859,300,000.

G) Sensitivity & caveats

• If attacker uses novel zero‑day that bypasses patching and allowlisting, reduction will be lower; however supply‑chain verification (Cosign/in‑toto) reduces risk significantly.
• Smaller firms have different cost/proportion; total EU impact depends on sector concentration and interdependencies.
• Operational maturity matters: misconfigured open‑source tools have limited effect.

Practical steps & 90‑day prioritized roadmap (for a large enterprise) making use of only open source tools

1. Days 1–14: Implement update proxy and require signature verification via Cosign/in‑toto for all vendor updates.
2. Days 1–21: Run OpenVAS full network scan to identify SMB/EternalBlue exposures; isolate vulnerable hosts.
3. Days 7–30: Deploy Ansible playbook to apply critical MS17‑010 patch and disable SMB v1 where possible.
4. Weeks 3–8: Deploy Suricata + Zeek sensors and integrate with OpenSearch; create alerts for SMB exploit indicators.
5. Weeks 4–12: Implement host controls (AppArmor/SELinux profiles), OSQuery inventory via FleetDM, and Wazuh agents.
6. Weeks 6–16: Configure immutable backups with Borg/Restic and test full restores from offline snapshots.
7. Weeks 8–20: Run tabletop exercises with TheHive playbooks and vendor‑supply chain verification processes.

Conclusion

A layered defence using free/open‑source tools—supply‑chain verification (Cosign/in‑toto), vulnerability scanning & rapid patching (OpenVAS + Ansible), network segmentation (pfSense), host allowlisting (AppArmor), NSM (Suricata/Zeek), and immutable backups (Borg/Restic)—could substantially reduce the risk and impact of a NotPetya‑style attack. Illustrative financial modeling shows that modest operational investments (low millions per large firm over three years) would likely have prevented tens to hundreds of millions in losses per affected firm and saved the EU economy many billions in aggregate, yielding very high ROI assuming correct deployment and ongoing maintenance.