Scheduled task change review

# Scheduled task change review

Compare observed daily tasks with a small approved baseline and distinguish exact maintenance approval from unexplained differences.

This is an original, fictional, offline exercise for an introductory security learner. It is independent practice, not copied coursework or a claim of professional experience. Completion and competence remain unassessed.

## Before you start

Allow **30-45 minutes**: 5 minutes reading, 10 inspecting and predicting, 10 checking and explaining, and 5-20 for a changed or independent case. You need Python 3.10+ (standard library only), a terminal and a text editor. Comfort opening files, reading a small table and basic evidence notes is enough; programming, administrator rights, a Linux installation and cloud accounts are unnecessary. Previous introductory network or Wireshark practice is useful but not required.

> **Vocabulary:** Baseline: the agreed comparison state. Run-as account: identity used by a task. Action: the configured executable path. Change approval: evidence authorising a specific change. Snapshot: a partial view at one time.

## Evidence and exact rules

The case JSON is the single authoritative input. Fixtures are guided.json, changed.json and challenge.json. All data is synthetic; artifacts is empty to avoid competing editable copies. Edit only a prepared run copy. The analyser is a pure calculation and never executes evidence text.

data has baseline, observed and approvals arrays. Rows have id, daily_time (24-hour HH:MM), account and literal action under fictional C:/Lab/. Approval rows also carry a nonempty reason. IDs are unique within each array. Approval IDs must be observed. No path is opened and no task command is run.

For each ID in baseline or observed, absent observed evidence gives missing-from-snapshot. An exact time/account/action match gives matches-baseline. Otherwise an exact approval tuple gives approved-maintenance-difference. A new ID without matching approval gives unregistered-task-review; another changed ID gives unapproved-change-review. Comparisons are literal and case-sensitive, not Windows path equivalence. Approval of one field never authorises differences in the others.

## Run the exercise

Open a terminal in this lab folder. Use your Python command (`python`, or `py -3` if that is how Python is installed). Commands below use `python` consistently.

```text
python lab.py cases
python lab.py prepare --scenario guided --out run/attempt-01
python lab.py show --case run/attempt-01/case.json
```

Read the evidence. In run/attempt-01/answers.json, fill each decision with an exact label from the rules; add an explanation and evidence references such as record IDs or configuration line numbers. In notes.txt, separate observation, interpretation, uncertainty, next check and help used. Save your prediction before opening the answer.

```text
python lab.py analyse --case run/attempt-01/case.json
python lab.py check --case run/attempt-01/case.json --answers run/attempt-01/answers.json
python lab.py prepare --scenario changed --out run/attempt-02
python lab.py prepare --scenario challenge --out run/attempt-03
python -m unittest -v test_lab.py
python lab.py verify
```

For changed/challenge use the corresponding attempt folder in show/analyse/check. prepare refuses an existing output folder. --out is relative to this lab and must be below run/; explicit input paths are relative to your terminal directory. analyse/show default to the guided fixture if --case is omitted. Exit 0 means command success or decision match; 1 means differences/incomplete written fields; 2 means invalid input or a filesystem problem. The checker verifies decision fields and the presence of writing, not the quality of reasoning. verify checks shipped examples, not learner mastery.

## Deliverable and limits

Keep case.json, answers.json and notes.txt together in the ignored run folder. Deliver a short handover: the question, your conclusion, two precise evidence references, one alternative explanation or limitation, and the next evidence you would request. State whether you used the worked example and whether you completed a fresh case unaided. Do not describe an automated match as assessment or professional experience.

Daily time, account and literal action path are compared exactly; this is not the Windows Task Scheduler XML parser. Matching an approval or baseline does not verify executable contents, actual execution, permissions or safety. No task was created or run.

Use WORKED-EXAMPLE.md after making a first prediction, and DRILLS.md for progressively less support. Do not use these rules as an operational security verdict or modify a real host as part of this exercise.

## Primary references

The following documentation supports the underlying concepts; the tiny schema and explicit teaching rules above are specific to this lab. Links were checked during authoring on 23 October 2026. Running the lab needs no internet connection.

- [Microsoft scheduled task fields](https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/schtasks-create)

# Worked example: Scheduled task change review

Try the guided case before reading this page. Use `python lab.py prepare --scenario guided --out run/worked-01` if you need a fresh ignored copy.

archive was approved for 02:00, lab-backup and C:/Lab/bin/archive.exe. Its observed 03:00 time exactly matches the maintenance approval, so the difference is explained by that note. inventory changes from 04:00/lab-inventory/C:/Lab/bin/inventory.exe to 04:00/SYSTEM/C:/Lab/temp/inventory.exe without an approval. Both account and path differ, so it needs review. A benign repair could explain the change, but that explanation must be checked; the snapshot alone does not establish persistence or malicious intent.

The reference decision fields for guided are:

```json
{
  "archive": "approved-maintenance-difference",
  "inventory": "unapproved-change-review"
}
```

Now open `python lab.py analyse --case run/worked-01/case.json` and compare observations, not only labels. Record one difference between your first prediction and the reference. If there was no difference, explain the rule that produced each decision rather than copying the label.

Handover prompt: explain what this evidence establishes, cite its exact IDs or lines, give a plausible alternative or remaining uncertainty, and name the smallest next check. Record any help used. A correct label by itself is not evidence of independent understanding.

# Drills: Scheduled task change review

## Guided practice

Prepare guided in a fresh run folder, read the README rules, and make a prediction for every decision ID. Use WORKED-EXAMPLE.md only after saving that prediction. Correct your explanation in a different paragraph so the original reasoning remains visible.

## Prompts only

Close the worked example and use these questions to reconsider the evidence:

- Which three fields must match an approval?
- Why is a missing row not enough to prove a task was deleted?

## Independent attempt

Prepare challenge in a fresh folder. Keep reference outputs, worked example and analyse closed until you have saved answers.json plus a five-sentence handover in notes.txt. Include the observation, interpretation, an alternative, uncertainty and next check. Use the README for syntax if needed and record that help. Afterwards run analyse/check and have a person inspect the explanation. Independent completion is unassessed unless someone actually reviews it.

## Changed case

Prepare changed. Predict which conclusions change and which do not. Explain the changed evidence before checking:

- What separates a new cleanup task from an existing task with changed settings?
- What collection check would you make before reporting inventory deleted?

Small edit drill: In the copied guided case, change only the approved archive time to 03:30. Predict whether the observed 03:00 task still matches the approval.

## Teach-back

Explain the difference between an authorised time change and an approval that does not cover the observed account or path. Use exact record IDs from your attempt. A partner should ask one counterexample rather than accepting a memorised label. Record the question and your response.

## Later recall

After 24-72 hours, reopen only your own notes and a fresh case. Write the central rule from memory, identify one boundary or missing-evidence condition and predict the result. Then check the documentation and record what you forgot. Do not count rereading an answer as an independent attempt.

## Handover

Keep the copied case, completed worksheet and notes together. State the scope, conclusion, two evidence references, unresolved uncertainty and requested next check. Include help used and whether someone assessed the reasoning. Do not claim experience beyond this fictional exercise.