Security incidents like data breaches, service disruptions and malicious attacks are bound to occur at some point, even in the most secure cloud environments. How organizations prepare for and respond to these incidents is crucial to minimizing damage and restoring normal operations quickly.
In this guide, we’ll outline an effective step-by-step approach to developing an incident response plan tailored for the cloud.
Why Incident Response Matters
Let’s first understand why incident response deserves dedicated planning in the cloud:
- Incidents can spiral rapidly – The wide network access and resources available in cloud environments enable threats to propagate quickly across systems.
- Evidence can be ephemeral – Incident data like system processes, network flows and log files can disappear rapidly in ephemeral cloud environments.
- Causes can be unclear – Complex application and infrastructure dependencies make pinpointing root causes of incidents challenging.
- Recovery is non-trivial – Rebuilding and redeploying distributed cloud systems is much harder than on-premises servers.
By preparing an incident response plan upfront, organizations can detect, investigate and recover from incidents more confidently.
Preparation: Building Cloud IR Capabilities
Effective incident response begins with upfront preparation across people, processes and technologies:
Establish Roles and Responsibilities
Clearly define responsibility for detecting, declaring, investigating, mitigating, recovering, and reviewing incidents among security, engineering and business teams.
Document Incident Types
Enumerate potential incident scenarios like data theft, service outage, supply chain compromise, insider threats, DDoS attacks etc. Create incident categories, priorities and severities.
Create Incident Handling Policies
Document required actions during incidents – communication protocols, escalation paths, evidence gathering, legal obligations etc. Make policies easily accessible.
Set Up Incident Monitoring Tools
Implement security monitoring tools like SIEMs, endpoint detection, and threat intelligence to detect incidents early. Establish log retention policies.
Enable Rapid Internal Communications
Set up alert distribution lists, war rooms, and always-on collaboration tools to streamline real-time communications during incidents.
Pre-negotiate External Contacts
Establish contacts with external agencies like law enforcement, regulators, and public relations who may need to be engaged during incidents.
Make Response Toolkits Accessible
Prepare investigative and diagnostic toolkits that can be rapidly deployed in response to cloud incidents.
Detection: Identifying Incident Triggers
The first step in incident response is effective detection. Monitor for these common cloud incident triggers:
- Increased failed login attempts – Unusually high rate of failed logins with invalid usernames/passwords.
- Multi-factor authentication failures – Sudden spikes in MFA errors and denials for users.
- Signs of account compromise – Unexpected password resets, application permission changes, and new user account creation.
- Unapproved cloud resource provisions – Surges in new cloud resources being created like storage, VMs, etc.
- Suspicious API calls – Calls to delete/modify resources, exfiltrate data, or modify security group configurations.
- Abnormal traffic volumes – Large unexplained surges in inbound or outbound network traffic beyond normal levels.
- Unusual user behavior – Cloud trail logs showing users accessing resources or data outside normal job duties.
- Malware identified – Cloud endpoint agents detecting malware execution and behavior anomalies.
- Service errors and failures – Unusually high application, network or authentication errors and service disruptions.
Any of these events should trigger further investigation. Use correlation rules and baselines tuned to your environment to detect outliers automatically.
Investigation: Determining Impact and Root Causes
Upon incident detection, focus first on determining scope and severity:
- Check health of cloud control services – Ensure core management services like CloudTrail, CloudWatch, IAM, authentication systems are functioning normally. Losing visibility into the environment will complicate investigation. Fix issues first if found.
- Identify affected resources – Check dashboards and alerts to identify unusual activity localized to any accounts, services, instances, functions or data stores.
- Confirm initial impact – Assess the tangible impact to applications and infrastructure from any unusual activity. Is it widespread or contained? Are critical systems impacted?
- Determine access anomalies – Check recent console logins, new user accounts, and API calls for suspicious access. Review permissions and roles assigned to users.
- Inspect network activity – Analyze flow logs and security groups for signs of data exfiltration, unusual internal traffic, and abnormal external connections.
- Check compromised hosts – Review security agent logs on cloud hosts and instances for indicators of compromise like suspicious processes, registry changes, and file modifications.
- Trace relevant events – Pivot through CloudTrail events and VPC Flow Logs around timeframes of detected anomalies to reconstruct sequences.
- Check threat intelligence – Query threat intel sources for recent attacks, identified signatures, and adversary behaviors relevant to the incident.
Mitigation: Isolating and Resolving Incidents
After gaining situational awareness, execute mitigations to contain damage and restore normal state:
- Isolate compromised resources – Suspend compromised user accounts. Block suspicious IP addresses. Quarantine and power down impacted hosts. Disable breached applications. The goal is to prevent threats from expanding impact.
- Rollback unauthorized changes – Reverse any undesirable configuration changes to permissions, security groups, services, and user policies detected during investigation.
- Reset user credentials – Have users reset passwords and rotate access keys to invalidate any credentials that may be compromised. Enable MFA globally if not already enforced.
- Apply temporary controls – To contain impact, consider temporarily blocking regions, stopping services, restricting IAM roles, or placing additional screening in front of applications while resolving an incident.
- Validate remediations – Once mitigations are deployed, re-check alerts, logs, and flows to confirm mitigations are working as expected. Make adjustments if incidents persist.
- Begin recovery – Assess long-term fixes needed like infrastructure and application changes, additional monitoring, and new security controls. Start implementing.
Recovery: Returning to Normal Operations
Restoring business as usual post-incident requires careful recovery planning:
- Identify damaged assets – Survey all resources, services, applications, endpoints, and data affected by the incident. Everything compromised should be rebuilt or re-secured.
- Restore data from backups – Utilize healthy backups to populate restored databases, file systems, object stores, and other data stores damaged by the incident.
- Rebuild compromised hosts – Instead of reusing compromised hosts, rebuild fresh cloud instances and hosts from known good configuration templates.
- Reset permissions – Remove unnecessary permissions and ensure least privilege roles across users, applications, and cloud services rebuilt after the incident.
- Harden security – Based on incident learnings, enable additional threat detection, access controls restrictions, multi-factor authentication, logging etc.
- Validate restorations – Confirm restored assets are properly patched, hardened, and configured before re-enabling access and use. Prevent re-compromise.
- Monitor for reoccurrence – Watch for signs of similar exploit or abnormal behavior that may indicate recovery was incomplete. Maintain heightened vigilance.
Post-Incident: Learning and Improving
After recovering from an incident, dedicate effort to learning and improving:
- Complete incident documentation – Finalize details like post-mortems, reports, and presentations required to share incident details with stakeholders and leadership.
- Identify root causes – Look at technical and process breakdowns that contributed to the incident occurrence, impact or extended duration. Prevent similar breakdowns.
- Review and update response plans – Analyze what worked and didn’t work in the incident response process. Improve and enhance response plans accordingly.
- Share lessons learned – Communicate within your organization and with partners about incident details, recovery, contributing issues, and lessons learned to improve collective response capabilities.
- Revisit security controls – Identify any gaps in security tooling, policies, configurations, training or practices that enabled the incident and led to cascading failures. Establish new controls and training.
- Update threat models – Factor new threat intelligence and tactics revealed by the incident into organization threat models and defenses.
Dissecting incidents drives continuous improvement of incident response and organizational resilience overall.
Conclusion
Effective incident response relies on preparation, rapid detection and containment, meticulous recovery, and continuous learning. With a structured plan tailored to cloud environments, organizations can manage incidents proficiently and strengthen defenses over time.
