Security checklist before moving legacy workloads to the cloud

A practical checklist de segurança para migração para cloud de workloads legadas inclui: inventário completo, classificação de dados, modelagem de ameaças, controles fortes de identidade, criptografia ponta a ponta, segmentação de rede e prontidão operacional. Para migração de sistemas legados para a nuvem em ambientes pt_BR, priorize validação e testes antes de qualquer cutover.

Pre-Migration Security Checklist Overview

• Confirm a complete inventory of legacy applications, interfaces, data stores and admin accounts, with owners identified.
• Classify data (e.g., public, internal, confidential) and define protection requirements before any cloud design.
• Document key threats, abuse cases and risk levels for each critical workload and integration.
• Enforce least-privilege IAM, MFA and strong auth flows for admins, services and migration tools.
• Apply encryption in transit and at rest, plus masking or tokenization for sensitive datasets used in tests.
• Design network segmentation, private connectivity and explicit allow-listing for all inbound and outbound flows.
• Validate monitoring, backup, recovery and incident response runbooks before switching production traffic.

Checklist item	Typical risk level if missing	Key validation steps
Asset inventory and data classification	High (unknown exposure surface)	Verify every workload has an owner, data category and environment tag; sampling shows no unidentified databases.
Threat modeling for critical flows	High (unmitigated attack paths)	Review at least top 5 data flows; confirm each has documented threats and mapped mitigations.
Strong IAM and MFA for admins	Critical (account takeover)	Attempt login without MFA and from new devices; access must be blocked or require step-up authentication.
End‑to‑end encryption	High (data interception or leakage)	Check that all endpoints enforce TLS and storage shows encryption enabled; no plaintext secrets in logs.
Network segmentation and access control	High (lateral movement in cloud)	Attempt to reach non-authorized services from test instances; connections must be blocked by default.
Monitoring, backups and IR readiness	High (undetected incidents, data loss)	Trigger a test incident and restore; confirm alerts fire and RPO/RTO targets are met.

Inventory and Classification of Legacy Assets

This section is critical for teams planning migração de sistemas legados para a nuvem, including regulated workloads in Brazil. It is less suitable if you are only experimenting with non-production sandboxes or if the legacy system is being fully replaced instead of migrated.

1. Map all legacy workloads and dependencies.
   • List applications, services, batch jobs, cron scripts and middleware currently in scope.
   • Identify upstream/downstream systems, including partner integrations and on-prem network segments.
   • Acceptance criterion: 100% of workloads in production CMDB or migration tracker have a unique ID and owner.
2. Classify data sensitivity for each asset.
   • Use categories aligned with your org (e.g., internal, confidential, highly confidential, regulated).
   • Flag workloads with PII, PHI, card data or financial records that impact how to migrar aplicações legadas para cloud com segurança.
   • Acceptance criterion: every database and file store has an assigned sensitivity level and data residency note.
3. Identify legacy security controls and gaps.
   • Review current authentication, logging, network ACLs, encryption and backup mechanisms.
   • Note custom cryptography, hardcoded secrets, unsupported OS or EOL middleware.
   • Acceptance criterion: each workload has a one-page security profile with at least three explicit gap entries or a statement of none.
4. Decide which assets should not move.
   • Exclude workloads blocked by licensing, data residency or hardware dependencies.
   • Consider decommissioning obsolete apps instead of migrating them.
   • Acceptance criterion: a signed decision record for every high-risk workload stating migrate, modernize, or retire.

Threat Modeling and Risk Prioritization

Before applying melhores práticas de segurança na migração para nuvem, prepare the following to model threats effectively and prioritize mitigation work.

1. Required inputs
   • Updated architecture diagrams for current state and target cloud design (at least high-level components and data flows).
   • Data classification results, including sensitive flows that cross trust boundaries (on-prem, cloud, partner).
   • List of business-critical transactions and regulatory requirements (LGPD, PCI, local financial regulations, etc.).
2. Tools and techniques
   • Simple threat modeling method (e.g., STRIDE or attack trees) and shared templates in your documentation tool.
   • Issue tracker or risk register to log threats, likelihood, impact and mitigation owners.
   • Optional support from serviços de consultoria para migração de sistemas legados para cloud when internal expertise is limited.
3. Access and stakeholders
   • Technical leads who understand legacy internals and planned cloud architecture.
   • Security engineer or architect to guide analysis and validate mitigations.
   • Product or business owner to confirm impact ratings and acceptable risk trade-offs.
4. Measurable outcomes
   • Top 10-20 threats per critical workload documented with explicit mitigations or risk acceptance.
   • Each critical data flow has at least one mapped control (e.g., TLS, tokenization, WAF rule).
   • Acceptance criterion: no high or critical threats remain without an assigned mitigation task and target date.

Identity, Access and Authentication Controls

Before the step-by-step instruction, consider these risks and limitations specific to identity and access when using any checklist de segurança para migração para cloud:

• Over-privileged migration accounts may be forgotten after cutover and abused later.
• Weak admin authentication can turn a small config mistake into a full environment compromise.
• Legacy apps that cannot support modern auth may require compensating network and monitoring controls.
• Inconsistent IAM across regions or clouds complicates incident response and audit.

1. Establish a cloud IAM baseline

   Define roles, groups and policies before granting any migration access.

   • Create separate roles for admins, read-only auditors, CI/CD and break-glass operations.
   • Prohibit use of long-lived root or owner accounts in daily work; keep them locked with hardware MFA.
   • Acceptance criterion: 0 production users log in with root/owner accounts in the last 30 days (audit logs verified).
2. Enforce strong authentication and MFA

   Secure all human and high-privilege access paths.

   • Require MFA for console access, VPN, bastion hosts and any jump boxes used during migration.
   • Use phishing-resistant methods (FIDO2, security keys) for cloud administrators when available.
   • Acceptance criterion: 100% of privileged accounts show MFA enabled and enforced in IAM reports.
3. Apply least privilege for migration tooling

   Constrain automated tools and scripts used for migração de sistemas legados para a nuvem.

   • Create dedicated service principals or roles with only the required actions on clearly scoped resources.
   • Ensure temporary elevation uses time-bound, approver-based workflows and is fully logged.
   • Acceptance criterion: no policy attached to migration identities grants wildcard actions on wildcard resources.
4. Integrate with enterprise identity provider

   Centralize access and simplify lifecycle management.

   • Configure SSO between corporate IdP and cloud accounts, using groups for role assignment.
   • Automate deprovisioning when employees leave or change roles.
   • Acceptance criterion: at least 90% of human logins to cloud consoles occur via SSO, not local users.
5. Secure legacy app authentication paths

   Handle systems that cannot adopt modern protocols immediately.

   • Place legacy apps behind secure gateways, WAFs or identity-aware proxies where possible.
   • Restrict access using network controls and device posture checks, especially for admin interfaces.
   • Acceptance criterion: all internet-facing legacy endpoints are fronted by a managed edge or WAF with TLS enforced.
6. Continuously monitor access behavior

   Detect misuse quickly before and after cutover.

   • Stream IAM and authentication logs into a central SIEM or logging platform.
   • Configure alerts for anomalous geography, time-of-day, privilege escalation and failed login spikes.
   • Acceptance criterion: at least four detection rules focused on privileged misuse are enabled and tested.

Data Protection: Encryption, Masking and Residency

Use this checklist to confirm that data protection is correctly implemented for migração de sistemas legados para a nuvem.

• All storage services for migrated workloads (block, file, object, databases) have encryption at rest enabled with managed or customer keys; metric: 0 unencrypted production data stores.
• All external and inter-service connections enforce TLS with modern cipher suites; metric: 0 successful plaintext connections observed in test captures.
• Sensitive datasets used in development, QA and performance testing are anonymized, masked or tokenized; metric: random samples show no real PII in non-production logs or DBs.
• Keys and secrets are stored in dedicated key management or secrets services, not in config files or images; metric: code and IaC scans find 0 hardcoded secrets before release.
• Data residency and localization requirements (e.g., storing certain records within Brazil) are mapped to specific cloud regions; metric: 100% of regulated datasets are deployed only in approved regions.
• Data lifecycle policies (retention, archival, deletion) are configured for logs, backups and snapshots; metric: all storage classes have an explicit retention setting, none left to unlimited by default.
• Backup data is encrypted and protected with separate access controls from production; metric: only backup operator roles can access backup vaults, verified by access review.
• Exports and ad-hoc data transfers (e.g., CSV dumps to S3) follow the same encryption and access rules; metric: all export buckets are private, encrypted and monitored for public ACL changes.

Network Segmentation and Secure Connectivity

Network design mistakes are common when applying melhores práticas de segurança na migração para nuvem. Watch for these pitfalls and address them early.

• Flat network topologies in the cloud that replicate legacy on-prem LANs, allowing broad lateral movement.
• Overly permissive security groups, NSGs or firewall rules using wide CIDR ranges or open ports to the internet.
• Mixing production, staging and development workloads in the same subnets or virtual networks.
• Relying solely on IP-based controls without considering identity-aware and application-layer protections.
• Unencrypted or misconfigured VPN/Direct Connect/ExpressRoute links between data center and cloud.
• Exposing management interfaces (SSH, RDP, DB consoles) directly to the internet instead of using bastion hosts or secure remote access.
• Ignoring DNS, name resolution and certificate management, resulting in insecure workarounds like hosts file hacks.
• Not updating network-based security monitoring (IDS/IPS, flow logs) to cover new cloud paths and services.
• Failing to document and review inbound third-party connections before migração de sistemas legados para a nuvem, leaving backdoors from partner networks.

Operational Readiness: Monitoring, Backups and Incident Response

Different organizations can choose from several secure patterns to reach operational readiness in a migração de sistemas legados para a nuvem. These alternatives can be mixed per workload.

• Fully managed cloud-native operations
  • Adopt provider-native monitoring, backup and incident tooling where possible, reducing custom complexity.
  • Best when teams are cloud-savvy and want tight integration with platform features.
  • Metric: at least 80% of alerts and backups for cloud workloads use native managed services.
• Hybrid operations with existing on-prem toolchain
  • Extend current SIEM, backup and ITSM tools to cover cloud workloads via agents and APIs.
  • Useful when migrating gradually and preserving existing SOC workflows.
  • Metric: all critical cloud workloads are visible in the central monitoring and ticketing systems.
• Outsourced managed security and operations
  • Leverage MSSPs or serviços de consultoria para migração de sistemas legados para cloud that also offer ongoing monitoring and IR.
  • Fits organizations with limited internal security staff or 24/7 coverage gaps.
  • Metric: clear SLAs for incident detection and response are defined and tested via quarterly exercises.
• Phased readiness with pilot workloads
  • Implement full monitoring, backup and IR only for a subset of workloads first, then scale.
  • Ideal when exploring como migrar aplicações legadas para cloud com segurança while learning from smaller pilots.
  • Metric: lessons learned from pilot incidents are documented and reflected in playbooks before expanding scope.

Common Security Concerns and Clarifications

Do I need a separate checklist for each legacy application?

Use one standard checklist de segurança para migração para cloud, but instantiate it per application or service. Each workload should have its own filled checklist, risk register and migration decision, all based on the same template.

How early should security be involved in the migration project?

Security should join as soon as you define scope and architecture for migração de sistemas legados para a nuvem. Involving them only before cutover typically leads to rework, delays and unresolved high-risk findings.

What if a legacy system cannot support modern authentication or encryption?

Apply compensating controls: strong network isolation, WAF or application gateways, strict admin access and enhanced monitoring. Document the residual risk and plan a modernization path after initial migration.

Is it safe to move regulated data to the cloud in Brazil?

It can be safe if you respect LGPD requirements, data residency constraints, encryption and access controls. Choose cloud regions and services that support compliance and document your controls for audits.

Should I migrate backups first or last?

Migrate or establish cloud backups early in the project so that new environments are protected from day one. Validate restore procedures before production cutover to avoid gaps in recoverability.

When do I need external consulting services?

Consider serviços de consultoria para migração de sistemas legados para cloud when you lack internal cloud security skills, face tight deadlines or handle high-risk regulated workloads. External experts can accelerate design reviews and threat modeling.

How do I know if the migration is secure enough to go live?

Use measurable acceptance criteria: no critical open risks, all high risks have mitigations in place, monitoring and backups tested, and change approvals recorded. A go-live checklist signed by security and business owners is recommended.