CTS - Computer Technology Specialists
Ransomware Recovery and Disaster Recovery Plan
A ransomware recovery plan addresses a specific and increasingly common disaster scenario — one where the attacker may have been in the environment for weeks before triggering encryption, and where backups themselves may have been targeted or compromised.
Melbourne IT support with visible local credentials
CTS - Computer Technology Specialists has supported Melbourne SMBs since 2000. Contact: 1300 790 780, hello@cts.au, L30 - 35 Collins St Melbourne 3000.
Certifications, affiliations and technology partners
Microsoft Partner, ACSC Essential Eight aligned, ISO 27001 practices, NBN Business Accredited Adviser, Cisco Partner, Dell Partner, HPE Partner, Arcserve Partner, Broadcom Partner, Kyocera Partner.
How ransomware recovery differs from general DR
Standard disaster recovery planning addresses hardware failure, site outage, or data loss. Ransomware recovery addresses an adversarial scenario with additional complexities: the attacker chose the timing of the attack and may have been resident in the network for weeks, the backup system may have been accessed and modified, decryption keys may or may not be available even if the ransom is paid, and the incident may trigger legal obligations around notification and evidence preservation. The recovery sequence, backup validation approach, and evidence handling are all different from general DR.
Dwell time and backup contamination risk
Modern ransomware groups typically dwell in a network for 7-21 days before triggering encryption — using this time to map the environment, harvest credentials, exfiltrate data, and access backup systems. This means that the most recent backups may have been taken while the attacker was resident in the environment. Recovery requires identifying the infection date and restoring from backups predating that date. Immutable backups with long retention (90+ days) are specifically designed for this scenario — the attacker cannot delete or encrypt historical backup data even if they access the backup management interface.
Isolating affected systems before recovery begins
Recovery cannot begin safely until affected systems are isolated and the attack vector is identified and closed. Attempting to restore encrypted systems to the same environment while the initial access vector remains open results in immediate re-infection. CTS follows an isolation-first protocol: disconnect affected systems, identify the initial access point (typically compromised credentials, phishing, or unpatched vulnerability), close the access point, then begin recovery in a clean environment. In cases where the entire domain is compromised, a full domain rebuild may be required before restoration.
Backup validation and clean restore
Before beginning restoration, validate that the selected backup predates the infection and is accessible and uncorrupted. Restore the backup to an isolated test environment and confirm the files are functional, unencrypted, and free from malware. For Microsoft 365 data, confirm that the third-party backup is accessible and that the most recent clean snapshot is available. Document the restore sequence — which systems come up first (typically domain controllers, then email, then file services, then line-of-business applications) and the validation steps for each.
Post-incident obligations — insurance and notification
A ransomware attack against an Australian business may trigger several obligations. If personal information was accessed or exfiltrated, the Notifiable Data Breaches scheme requires notification to the OAIC and affected individuals within 30 days of determining that a notifiable breach occurred. If a cyber insurance policy is in place, the insurer must be notified promptly — delays in notification may affect coverage. Preserve forensic evidence (network logs, system logs, the ransom note, attacker communications) before beginning remediation, as these may be required by the insurer, law enforcement, or legal counsel.
How CTS builds ransomware-ready DR for Melbourne businesses
CTS designs ransomware-resistant backup and DR architectures for managed IT clients: immutable cloud backup with 90-day retention, Microsoft 365 backup with point-in-time restore, documented recovery sequences and runbooks tested annually, and a defined incident response procedure including insurer notification contacts. For managed IT clients, CTS manages the full incident response if a ransomware attack occurs — including isolation, forensics engagement coordination, backup validation, and environment recovery.
Frequently asked questions
How is ransomware recovery different from standard disaster recovery?
Standard disaster recovery addresses hardware failure or accidental data loss. Ransomware recovery is adversarial — the attacker may have been in the environment for weeks, specifically targeting backups before triggering encryption. Recovery requires identifying and closing the initial access vector before restoring, validating that backups predate the infection, and often rebuilding into a clean environment rather than restoring to the same infrastructure. Immutable backups with long retention periods are specifically designed for this scenario.
What should we do first when we discover ransomware?
The first actions are isolation and escalation: disconnect affected systems from the network immediately to stop the spread, notify your IT provider and cyber insurance incident response line, and preserve forensic evidence before beginning remediation. Do not pay a ransom without legal and insurance advice. Do not turn off infected servers before a forensic image is taken if law enforcement involvement or insurance claims are anticipated — running memory may contain decryption keys.