Incident Response Planning: Building a Cyber Resilience Framework

Every organization will face a cybersecurity incident—the question is not if, but when and how prepared you are to respond. Incident response (IR) planning transforms chaotic, ad-hoc reactions into structured, efficient processes that minimize damage, reduce recovery time, and preserve evidence for forensic analysis. Organizations with tested IR plans contain breaches 54 days faster on average, according to industry reports. At Nexis Limited, we help organizations build incident response capabilities that turn security incidents from catastrophic events into manageable operational challenges.

Building the Incident Response Team

An effective IR team extends beyond the security department. The core team includes: an Incident Commander who coordinates the overall response and makes escalation decisions; security analysts who perform technical investigation and containment; systems administrators who execute containment actions and support recovery; and a communications lead who manages internal and external messaging. Extended team members are activated as needed: legal counsel for regulatory obligations and liability assessment, HR for insider threat incidents, public relations for external communications, and executive leadership for strategic decisions. Every team member must understand their role before an incident occurs—confusion during an active incident costs precious response time.

Developing Incident Response Playbooks

Playbooks are step-by-step procedures for handling specific incident types. Rather than a single generic plan, develop tailored playbooks for: ransomware infection, business email compromise, web application breach, insider threat, DDoS attack, data exfiltration, and compromised credentials. Each playbook should include: detection criteria and initial assessment steps, severity classification guidelines, containment actions (both immediate and extended), evidence collection procedures, eradication and recovery steps, and communication templates. Playbooks should be specific enough to guide action under pressure while flexible enough to accommodate the unique characteristics of each incident.

Severity Classification

Not all incidents require the same level of response. Define severity levels with clear criteria: Critical (active data exfiltration, ransomware encryption in progress, compromise of critical infrastructure), High (confirmed unauthorized access to sensitive systems, ongoing attack requiring immediate containment), Medium (malware infection on isolated endpoint, phishing compromise of non-privileged account), and Low (reconnaissance activity, policy violations, false positive requiring investigation). Severity determines escalation paths, response timelines, and communication requirements. A critical incident might require executive notification within 30 minutes, while a low-severity incident follows standard business-hours workflow.

Containment Strategies

Containment is the most time-critical phase of incident response. Short-term containment stops the immediate bleeding—isolating affected systems from the network, blocking malicious IP addresses at the firewall, disabling compromised accounts, and revoking stolen credentials. Long-term containment involves implementing temporary fixes that allow business operations to continue while the root cause is investigated—deploying additional monitoring on affected segments, implementing emergency firewall rules, and standing up clean replacement systems. The containment strategy must balance the need to stop the attack with the requirement to preserve forensic evidence.

Digital Forensics and Evidence Preservation

Forensic evidence must be collected and preserved according to established procedures to support investigation and potential legal proceedings. Key evidence sources include: volatile memory captures from affected systems (using tools like WinPMEM or AVML), disk images of compromised hosts, network packet captures from the relevant time window, SIEM logs and authentication records, cloud platform audit trails, and email headers from phishing messages. Maintain a chain of custody for all evidence, documenting who collected it, when, how, and where it is stored. Forensic analysis should determine the attack timeline, initial access vector, lateral movement path, and full scope of compromise.

Post-Incident Review and Improvement

The post-incident phase is where organizational learning occurs. Conduct a blameless post-mortem within one to two weeks of incident resolution. Document: the complete incident timeline from first indicator to full recovery, what detection mechanisms worked and what failed, how well playbooks and procedures served the response team, communication effectiveness both internally and externally, and specific improvement actions with assigned owners and deadlines. Feed improvements back into prevention controls, detection rules, playbooks, and training programs. Track improvement actions to completion—an unimplemented lesson learned is a lesson wasted.

In Bangladesh's rapidly digitizing economy, cyber resilience is a business imperative. Organizations that invest in incident response preparedness protect not just their data and systems, but their reputation and customer trust. Contact us to develop an incident response framework tailored to your organization's risk profile, regulatory requirements, and operational capabilities.