# Incident: Analyst-selected activity for investigation

**Case:** CASE-SEED  
**Generated:** 2026-09-26 11:12:46 UTC  
**Status:** complete  
**Severity:** MEDIUM  |  **Grouping confidence:** low  
**Hosts:** CLIENT1  
**Accounts:** client1  
**Window:** 2024-12-28 15:02:06 -> 15:02:06 UTC (0s)

> This report was produced by an automated investigation over telemetry from: **winlogbeat**. It presents evidence-backed findings for analyst review and does not authorise or perform any response action.

## Verdict

**Disposition:** Benign  
**Engine:** d1  |  **Profile:** operational-v6  |  **Model:** qwen3.5:9b  
**Decided by:** the model's concluding round  
**Evidence basis:** 1 of 1 cited event id(s) name events the investigation retrieved; 5 typed observation(s) checked against recorded telemetry; 0 claim(s) rejected by verification; 1 probe(s) run; 3 tool call(s) served, 0 refused.  
**Evidence gap (model-written):** "none"  
**Supporting event ids:** `wlb-process-0001058` (retrieved)

*This system does not compute a confidence score for its verdict. The evidence basis is a count of what was checked, not a measure of how likely the verdict is.*

## Investigation Tree

```text
Initial alert: Analyst-selected activity for investigation
  rules ANALYST-SEED; 1 seed event(s): wlb-process-0001058
  ↓
ATH investigation (engine d1)
  └── process_tree (device='CLIENT1', pid=9284, process_guid='sysmon:416dd0c5-12ee-6770-2904-000000000c00')
        model's reason: "Need to inspect child processes of firefox.exe (pid 9284) to determine if any suspicious commands or scripts were executed."
        new events: 2 retrieved; shown: wlb-process-0001057, wlb-process-0001055
  stopped: model chose no probe
  ↓
Verdict: Benign
```

## Reasoning Summary

*Quoted text below is model output, reproduced verbatim. It is not verified fact: the checks applied to it cover the event ids it cites and any typed premises it declared, not what its sentences assert. Each cited id is marked by whether it names an event the investigation retrieved.*

1. **Model label: benign** -- verifier: accepted
   > Model wrote: "The observed process is a standard user-initiated launch of Firefox to open a local PDF file. The command line shows no suspicious arguments, and the process tree confirms no malicious children or network exfiltration occurred."
   - Cited: `wlb-process-0001058` (retrieved)

## Executive Summary

This report covers CASE-SEED, correlating 1 detection finding(s) across 1 host(s) (CLIENT1) and 1 account(s) (client1) between 15:02:06 and 15:02:06 UTC on 2024-12-28. 5 statement(s) below are directly established by telemetry, 4 are evidence-supported inferences, and 0 are explicitly unverified hypotheses requiring analyst confirmation. This report does not authorise or perform any response action. All recommendations below require human review before action is taken.

## Attack Timeline

| Time | Rule | Severity | User | Host / Movement | ATT&CK | Events |
| --- | --- | --- | --- | --- | --- | --- |
| 15:02:06 | ANALYST-SEED | MEDIUM | client1 | CLIENT1 | - | wlb-process-0001058 |

## Findings

### Confirmed (FACT) (5)

*Typed observations checked against recorded telemetry.*

- Confirmed: Event wlb-process-0001058 records process identity sysmon:416dd0c5-12ee-6770-2904-000000000c00.
  - Evidence: `wlb-process-0001058`
- Confirmed: Event wlb-process-0001055 records process identity sysmon:416dd0c5-12ed-6770-2604-000000000c00.
  - Evidence: `wlb-process-0001055`
- Confirmed: Event wlb-process-0001057 records process identity sysmon:416dd0c5-12ee-6770-2804-000000000c00.
  - Evidence: `wlb-process-0001057`
- Confirmed: Process event wlb-process-0001057 identifies the instance in wlb-process-0001055 as its parent.
  - Evidence: `wlb-process-0001055, wlb-process-0001057`
- Confirmed: Process event wlb-process-0001058 identifies the instance in wlb-process-0001057 as its parent.
  - Evidence: `wlb-process-0001057, wlb-process-0001058`

### Assessed (INFERENCE) (4)

*Interpretations and summaries; citation or predicate checks do not verify their free-text meaning.*

- Assessed: Unverified summary: ANALYST-SEED (MEDIUM) on CLIENT1 under account client1: Analyst-selected activity for investigation. An analyst selected these events for review. The selection says where to look; it is not a detection and carries no verdict.
  - Evidence: `wlb-process-0001058`
- Assessed: Unverified summary: The case's cited telemetry comprises 1 of 1 event(s), from 2024-12-28T15:02:06+00:00 to 2024-12-28T15:02:06+00:00.
  - Evidence: `wlb-process-0001058`
- Assessed: Unverified summary: On CLIENT1, firefox.exe (PID 9284) ran under account client1 with execution chain - -> cmd.exe -> firefox.exe -> firefox.exe, spawning no observed child process. Resolution: identity.
  - Evidence: `wlb-process-0001058, wlb-process-0001057, wlb-process-0001055`
- Assessed: [benign] The observed process is a standard user-initiated launch of Firefox to open a local PDF file. The command line shows no suspicious arguments, and the process tree confirms no malicious children or network exfiltration occurred.
  - Evidence: `wlb-process-0001058`

### Unconfirmed Hypotheses (0)

*Possible explanations that have NOT been verified. Treat as open questions for the analyst, not as findings.*

_None._

## Evidence Checks

5 typed observations verified; 3 unstructured summaries retained as interpretations.

Predicate support does not establish malicious intent or verify the accompanying prose.
- process_identity [wlb-process-0001058]: **supported** — recorded process identity: sysmon:416dd0c5-12ee-6770-2904-000000000c00

## Recommended Next Steps

*These are investigative recommendations for a human analyst. No response action has been taken or is authorised by this report.*

1. **Retrieve email gateway or web-proxy logs to establish the initial access vector.**
   - Rationale: No detection in this case targets initial access, so the delivery mechanism (e.g. a phishing attachment) is inferred from process lineage rather than confirmed from delivery telemetry.
   - Based on: MITRE ATT&CK tactic coverage gap: Initial Access
2. **Escalate to a human analyst for validation before any remediation action is taken.**
   - Rationale: This system performs read-only investigation only. It has no capability to disable accounts, isolate hosts, or otherwise remediate, and this report is not authorisation to do so.
   - Based on: system design constraint

## Limitations & Scope

- Telemetry underlying this report came from: winlogbeat. Field coverage depends entirely on what the originating export or sensor captured; this project's canonical schema does not model every field a real EDR product exposes (e.g. file hashes, signer information, session identifiers), and any of those were dropped during normalization.
- ATT&CK mappings are interpretations of observed behaviour against a public taxonomy. They indicate that behaviour is consistent with a technique, not that an adversary performed it.
- Grouping confidence describes how strongly correlated findings are linked to each other, not whether an intrusion occurred.
- No evidence was found for the following ATT&CK tactics: Initial Access, Discovery, Credential Access, Lateral Movement, Collection, Exfiltration. Their absence may reflect that the activity did not occur, or that available telemetry cannot observe it.
- Typed predicates are checked against recorded telemetry; free-text interpretations are not semantically verified. Missing identity is not a confirmed process link, and recorded event order does not establish causation.
- disposition: benign
- evidence gap: none

## Investigation Trace

Agents run: investigator:seed, investigator:probe, investigator:conclude  
Tool calls made: 3

- step 1: investigator:seed -- findings, cited rows, techniques
- step 2: investigator:probe -- P1 process_tree: Need to inspect child processes of firefox.exe (pid 9284) to determine if any suspicious commands or scripts were executed.
- conclude: 1 explanation(s) proposed, 0 with out-of-scope citations dropped; disposition benign
- conclude: accepted 1, rejected 0
- stop -- model chose no probe
- evidence verification: 5 checked observations; 3 summaries reclassified

## Evidence Appendix

All 3 telemetry events underlying this report, chronologically. Every claim above cites specific event ids from this list.

| Event ID | Time | Device | User | Summary |
| --- | --- | --- | --- | --- |
| `wlb-process-0001055` | 15:02:05 | CLIENT1 | client1 | - -> cmd.exe \| C:\Windows\system32\cmd.exe /c ""C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe" C:\Users\client1\Documents\attachments\trial.pdf" |
| `wlb-process-0001057` | 15:02:06 | CLIENT1 | client1 | cmd.exe -> firefox.exe \| "C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe"  C:\Users\client1\Documents\attachments\trial.pdf |
| `wlb-process-0001058` | 15:02:06 | CLIENT1 | client1 | firefox.exe -> firefox.exe \| "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" C:\Users\client1\Documents\attachments\trial.pdf |