Cybersecurity & Information Security

Ransomware Investigation: The First 60 Minutes

6 min readPublished: August 5, 2026

Professional visual illustration of Ransomware investigation in Incident Response and DFIR

Quick answer

Ransomware investigation is a controlled process that balances damage containment with evidence preservation. Document the source, time, and tools, save the Hash, build a Timeline, and separate fact, interpretation, and decision.

Incident Response and DFIR require a balance between speed, evidence preservation, business continuity, and documentation. A correct action is an action that can be explained, reproduced, and reviewed after the incident. This article focuses on Ransomware investigation and is intended for analysts, IT, and team leaders. The goal is to provide a work methodology that can be applied in practice, in a professional interview, and in a work environment, without settling for a dictionary definition.

The central challenge is that the data is almost always partial. Scope, isolation, identity containment can indicate a direction, but their meaning depends on the time, asset, user, and expected activity. Therefore, the examination will be built around an investigation question, required evidence, and a clear criterion for completion.

The practical scenario in the article is: a Tabletop exercise for minutes 0-15, 15-30, and 30-60. All examples are laboratory data or process descriptions. When dealing with Penetration Testing, Web, or Cloud, one should only work with explicit authorization, a defined Scope, and the ability to stop the test.

Incident Verification

A professional Ransomware investigation begins with success and failure conditions. Define a positive case, a negative case, a boundary case, and similar legitimate activity. This allows for the identification of both False Negative and False Positive.

In an authorized environment, use minimal action that proves the claim without causing damage. Save Input, Output, time, and version, and after correction, perform a Retest in the same scenario and also check for Regression on adjacent functions.

Isolation and Containment

The response to a Ransomware investigation should minimize risk without deleting evidence that is still needed. Start with a reversible and focused action, confirm ownership and authority, and document time, perpetrator, and result.

Long-term remediation addresses the root cause: permissions, configuration, Validation, Telemetry, process, or training. After implementation, perform a Retest and monitor for signs of recurrence, rather than just closing the Ticket.

Scoping Users and Hosts

The topic 'Scoping Users and Hosts' is a central part of working on a Ransomware investigation. It is recommended to break it down into three questions: what is the input, what decision needs to be made, and what evidence is sufficient to justify it. These questions prevent automatic tool use without understanding the objective.

In practice, document scope, isolation, identity containment, backup protection, volatile evidence, compare to expected behavior, and define at least one Pivot. The result should be verifiable by another analyst, including limitations and next steps.

Evidence and Backup Preservation

At this stage, define what evidence is needed to answer the investigation question. For a Ransomware investigation, the basic points are the evidence source, collection time and time zone, Hash and Chain of Custody, tool and version. For each source, document owner, retention period, time zone, ingestion delay, and potentially missing fields.

Collection quality is not measured by the log 'arriving'. It is necessary to check Completeness, Latency, Parsing, Duplicate events, and time synchronization. A Canary test or a known lab incident allows verifying that the activity appeared at the source, passed through the Pipeline, and can be searched in the correct fields.

Communication and Further Investigation

A Ransomware investigation begins by formulating a Hypothesis: what behavior explains the finding, and what evidence will confirm or refute it. Then, expand the time window, verify the entities, and look for a sequence before and after the incident.

Good correlation combines at least two types of information from scope, isolation, identity containment, backup protection, volatile evidence, communications. For each finding, state what it proves, what it does not prove, and what the next step is. If the data is insufficient, mark it Unknown and do not turn absence of evidence into evidence of absence.

Unique Examination Points

On this topic, it is recommended to build a focused evidence map in advance. The main examination points are: scope, isolation, identity containment, backup protection, volatile evidence, communications. The list is not an automatic Checklist; each item is chosen because it can link an entity, action, and time or explain legitimate behavior.

scope: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
isolation: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
identity containment: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
backup protection: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
volatile evidence: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.
communications: Define the expected value, what would be considered anomalous, and what additional source would verify the finding.

When one of the focal points is unavailable, document the gap and choose an alternative. For example, if Process identifier is not stable, one can use time, Host, User, and Parent; if Payload is encrypted, use Metadata, volume, frequency, and TLS/DNS context.

Recommended Workflow

Define Scope and one working question for Ransomware investigation.
Document the data sources and required evidence: scope, isolation, identity containment, backup protection.
Create a short Baseline of normal behavior or expected outcome.
Perform the minimal test in a lab environment and save time, input, and output.
Build a Timeline or comparison table and separate fact from interpretation.
Pivot to an additional source to confirm or refute the initial explanation.
Summarize the decision, limitations, recommended action, and Retest criterion.

Practical Scenario

The chosen scenario is a Tabletop exercise for minutes 0-15, 15-30, and 30-60. The purpose of the exercise is not to prove attack capability, but to practice collecting, comparing, and documenting safely. Before starting work, define simulated data, a time window, and an expected outcome.

At the end of the exercise, a product that another analyst or tester can review must be submitted: a screenshot or Export of the evidence, a short Timeline, initial assumption, confirming evidence, limitation, and recommendation. When there is insufficient evidence, the correct conclusion is that the scenario was not proven.

Stage	What is performed	Output
Preparation	Define Scope, time, and objective. Document which fields or evidence from scope, isolation, identity containment are expected to appear.	Short test plan
Data Creation	Perform a safe and simulated action related to Ransomware investigation, without real information or impact on a production system.	Controlled event/Request/Flow
Collection	Collect the raw evidence and context from another source. Ensure Time zone, identifiers, and completeness.	Two linked pieces of evidence
Analysis	Write what each piece of evidence proves, what it does not prove, and what is the possible legitimate explanation.	Interim conclusion
Completion	Choose closure, escalation, Finding, or Tuning; add recommendation and Retest.	Documented output

Practical Checklist

Check and document: Evidence source.
Check and document: Collection time and time zone.
Check and document: Hash and Chain of Custody.
Check and document: Tool and version.
Check and document: Response actions performed.
Check and document: Timeline and working assumptions.
Specify Time zone, tool version, and collection time.
Save the raw data before filtering or modification.
Write what the finding proves and what is still unknown.
Define owner and next action with a deadline.

Common Mistakes

Modifying the system before preserving evidence.
Not documenting the time zone.
Not calculating Hash.
Mixing fact and speculation.
Not documenting who held the evidence.
Prioritizing theoretical completeness over immediate damage containment.

Summary and CTA

Ransomware Investigation: The First 60 Minutes is a topic that connects technical knowledge with work discipline. Start with a question, collect only relevant evidence, preserve context and time, and choose an action that can be justified and re-examined.

In HPI's Cybersecurity & AI program, these principles are practiced using systems, logs, and labs. A natural continuation is to proceed to the linked articles, perform the lab exercise, and save the output as part of a professional portfolio.

FAQ

Does Ransomware investigation alone prove an attack or weakness?

No. It provides a signal or finding that requires context, validation, and an additional source. A professional conclusion relies on a sequence of evidence and alignment with expected behavior.

What to do when some data is missing?

Document the missing data, check for an alternative source, and reduce the level of certainty. Do not complete fields with speculation or present Unknown as valid.

How long should evidence be retained?

The retention period depends on policy, regulation, cost, and the type of incident. It is important to define Retention, Legal hold, and the ability to export evidence in a verifiable format in advance.

How to practice without risking a real system?

Use virtual machines, simulated data, CTF, or a dedicated lab. In authorized tests, define Scope, Stop conditions, and backup before starting work.