What is ransomware incident response?
Ransomware incident response is the coordinated work an organization carries out from the moment ransomware is discovered until systems are running again and the incident is formally closed. It covers scoping the damage, cutting off the attacker, preserving evidence, restoring from clean copies and handling the reporting that follows.
Cyber incident response phases applied to ransomware
Cyber incident response is the general discipline for handling any security incident, from a phished mailbox to a misconfigured bucket, and ransomware is its most demanding case. The common reference is NIST SP 800-61, whose long-standing model runs from preparation, through detection and analysis, to containment, eradication and recovery, and then post-incident activity. Revision 3, published in 2025, maps that work onto the functions of the NIST Cybersecurity Framework 2.0.
In a ransomware case the phases overlap heavily. The most critical systems are often restored while eradication is still under way elsewhere, one reason restores go to an isolated environment first. Preparation shows its worth in the first hour: a contact list, runbook or vault of backup console passwords kept only on domain-joined systems is unreachable once the domain is encrypted.
Who sits on the first call
The backup administrator is part of the response from the start, alongside security staff, IT management, legal counsel and often the cyber insurer with an outside response firm it has approved. Each asks the backup side for something different:
- Management: whether the backups survived and when the business runs again.
- The response firm: job logs, console sign-in records and access-key usage.
- Legal counsel: which data was reachable, which drives the notification decisions.
- The insurer: adherence to its procedures, including who may talk to the attacker (see cyber liability insurance).
In a small team, the person answering all four is also rebuilding the backup server and running the first restores. MSPs face the same questions once per tenant on the affected platform, plus one more: whether any other customer was exposed.
Containment steps that cut off recovery
| Containment step | Effect on recovery |
|---|---|
| Disconnecting the backup server | Stops further deletion through the console, and stops any jobs still running |
| Resetting domain administrator passwords | Leaves S3 access keys and local backup accounts valid until rotated separately |
| Rotating repository access keys | Locks the attacker out of the storage, and breaks backup jobs until they are reconfigured |
| Powering off infected servers | Halts encryption, and loses the memory evidence of how the attacker operated |
| Restoring straight into production | Brings services back sooner, at the risk of restoring the foothold with the data |
Forensic evidence in restore points and storage logs
Data breach forensics, the collection and analysis of evidence showing how an attacker got in and what they reached, leans on the backup system more than most plans assume. Restoring older copies of a compromised server into an isolated environment lets investigators find the first day a malicious tool or account appears, and that date marks the earliest restore point treated as clean. Evidence is fingerprinted with a hash at collection and tracked through a chain of custody.
Retention limits what can be proven. If logs cover 30 days and the intrusion began 45 days before discovery, the first 15 days leave no record, and regulators or insurers may assume the worst about that period. Evidence kept where an intruder could edit or delete it also carries less weight.
ARTESCA and ransomware incident response
ARTESCA can send its storage audit trail to a SIEM or log platform such as Splunk, Elasticsearch, Graylog or a syslog server, so a record of every request sits outside the system under investigation and responders can check whether the repository was touched without trusting consoles the attacker may have used. A legal hold under S3 Object Lock keeps evidence files or backup sets locked with no end date until the hold is removed, while compliance-mode retention holds restore points until their retain-until date.
Rotating the backup application's keys and rebuilding the backup server remain tasks for the response team.
Related terms
- Ransomware recovery: the restore sequence that follows containment.
- Breach detection: how the incident is first noticed.
- Data breach: the notification duties forensics findings feed into.
- Backup tampering: evidence of what the attacker did to restore points.
- Clean room recovery: where investigators examine older restore points.