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DFIR JUN 2026 · 6 MIN read

The first 4 hours of a ransomware, told from the shift

Anonymized case: which decisions mattered and what a retainer would have changed.

IR
DFIR team
Incident response
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THE ESSENTIALS

The first hour's decisions determine whether the incident lasts three days or three weeks.

Powering off the machines destroyed volatile memory, the best evidence was lost before our first call.

With a retainer, the team already knows the environment: this case's four hours would have shrunk to under one.

A Friday, 11:40 p.m., the call comes in: the billing server’s files have a strange extension and there’s a ransom note on the desktop. The organization was not a CROC client and had no retainer. What follows is the reconstruction of the first four hours, with the affected party’s permission and no identifying data.

Hour 0 to 1: the decisions already made

Before calling us, the IT team did what instinct dictates and forensics laments: powered off the affected servers. Volatile memory, running processes, connections, encryption keys in some cases, was lost. The first instruction of the call was to touch nothing else: isolate from the network yes, power off no.

FIRST HOUR · ACTUAL SEQUENCE

23:40  incoming call · initial triage
23:55  preliminary scope: 1 server + 12 workstations
00:10  network isolation of the affected segment
00:25  variant identified from the note
00:40  initial-access hypothesis: VPN without MFA
00:55  emergency credentials rotated

Hour 1 to 4: containing without evidence

Without prior telemetry, every basic question, since when are they inside? what did they take?, required hours of reconstruction from the logs that survived. The VPN without a second factor turned out to be the access; it had been exposed for months. Encryption was contained to the isolated segment and restoration started from verified backups that same night.

The retainer doesn’t do magic. It makes the 11:40 p.m. call not start from zero.

WHAT A RETAINER WOULD HAVE CHANGED

Agreed runbook (nobody powers off servers), telemetry already connected (scope answered in minutes, not hours), pre-authorized remote access (containment within the first hour) and agreed rates (nobody negotiates prices during a crisis). This case’s four hours would have shrunk to under one.

The organization is today a CROC client with a retainer. Its annual tabletop reproduces, with its own team, exactly this sequence.

Material like this, every week.

The CERT-CBRT bulletin: what is being exploited in the region and what the shift learns by operating. No marketing.