OpenCyber Academy
Rapid course · Lesson 1 · English
Course code: OCA-012Lesson 01: OCA-012-A001

Week 1: Know your devices and update them

Open, free learning for anyone who wants to protect people and technology. No account is required to read this text or its worked answers.

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Public activity · 30d

—Participating browsers

—Page views

—Reading sessions

—Exercise opens

Counts reflect browsers that allowed analytics. A reading session requires 30 seconds on a visible page. Browsers are not people.

Learning outcomes

You will (1) list every device and who uses it; (2) run a five-point quick check; (3) get updates working everywhere.

1.1 The case

Leah Morgan volunteers as the IT lead at the fictional Fenwick Community Food Bank, which has twelve laptops used by staff and volunteers, a shared PC at the front desk and a cloud email and file service. Leah is taking the one-month rapid course from the fictional Northgate Learning. Last month a volunteer's laptop was stolen from a car, and nobody could say whether it was encrypted or what was on it. The trustees asked Leah to make sure that does not happen again, with no budget beyond what the food bank already pays for.

1.2 Start with a list

You cannot protect what you do not know about. CIS Controls v8 starts with an inventory of devices for this reason. Leah makes a simple spreadsheet with one row per device: a short name, who uses it, model, serial number and where it normally lives. She finds the twelve laptops, the front desk PC and an old laptop in a cupboard that nobody uses, which is wiped and recycled.

The serial number column answers the question the theft raised: with it, the food bank can tell the police and the insurer exactly which device was taken. The "where it lives" column matters for the same reason; a laptop that normally goes home in a volunteer's car carries more risk than one that stays in the office.

1.3 The quick check

Leah checks five things on every laptop, because together they cover the most common harms: updates installed within fourteen days, disk encryption on, the user working in a standard account rather than an administrator, a screen lock, and files backed up in the last week. Each is a yes or no.

Each check maps to a part of the stolen-laptop problem. Encryption decides whether a thief can read the disk. Backups decide whether the food bank loses work. Updates and a standard account make it harder for a harmful program to take over a laptop in the first place. A screen lock protects a laptop left open on the front desk. Recording yes or no keeps the check quick enough to repeat every month.

Lab — Five-point quick check

"""Five-point quick check across a small charity's laptops (synthetic, stdlib only)."""
checks = ["updates<=14d", "encrypted", "standard user", "screen lock", "backup<=7d"]
laptops = {"FB01": [1,1,1,1,1], "FB02": [1,0,0,1,1], "FB03": [0,1,1,1,0], "FB04": [1,1,0,1,1], "FB05": [1,1,1,0,1],
           "FB06": [1,0,1,1,1], "FB07": [0,0,0,1,0], "FB08": [1,1,1,1,1], "FB09": [1,1,0,1,1], "FB10": [1,1,1,1,0],
           "FB11": [1,0,1,1,1], "FB12": [1,1,1,1,1]}
for i, c in enumerate(checks):
    print(f"{c:14} {sum(v[i] for v in laptops.values()):2d}/{len(laptops)}")
full = [k for k, v in laptops.items() if all(v)]
print(f"laptops passing all five: {len(full)}/{len(laptops)}; worst: {min(laptops, key=lambda k: sum(laptops[k]))}")

Run with python3 lab_quickcheck.py. Verified output:

updates<=14d   10/12
encrypted       8/12
standard user   8/12
screen lock    11/12
backup<=7d      9/12
laptops passing all five: 3/12; worst: FB07

1.4 Reading the result

Only three of twelve laptops pass all five. Encryption and standard accounts are weakest at eight of twelve each. FB07 fails four checks: it is an old laptop used by a weekend volunteer. Screen lock is nearly everywhere already. This tells Leah where to spend her four weeks.

The lab's per-laptop rows show where the gaps sit. FB02, FB06, FB07 and FB11 are not encrypted; FB02, FB04, FB07 and FB09 have users working as administrators; FB03 and FB07 are behind on updates; FB03, FB07 and FB10 have no recent backup; and only FB05 lacks a screen lock. FB01, FB08 and FB12 pass everything. Encryption comes first because it is exactly what nobody could confirm for the stolen laptop.

1.5 Getting updates working

Two laptops are behind on updates. One has a full disk; the other has updates paused. Leah frees space, removes the pause and sets updates to install automatically with a restart outside opening hours. She also checks that the browser and PDF reader update themselves. NIST SP 800-40 Rev. 4 describes patching as preventive maintenance; for a small charity, that means making automatic updates work and checking them monthly.

Both problems were invisible to the users: a laptop with paused updates keeps working normally until the day a known flaw is used against it. Fixing the cause matters more than installing the missing updates once. A full disk will fill again, so Leah moves old files to the cloud service as well as clearing space. By Friday all twelve laptops show updates within fourteen days.

Worked example

Leah fills in the spreadsheet in an afternoon, runs the quick check over two days as volunteers come in, and fixes the two update problems the same week. By Friday, all twelve laptops show updates within fourteen days.

Synthetic case. Fenwick Community Food Bank, Northgate Learning and all people and data are fictional; figures are synthetic.

Errors and limits

Assuming a laptop is fine because it seems to work is how the stolen laptop's status went unknown. Check, record and date it.

Exercises

  • EX001 — Inventory first. Why does the course start with a device list?
    Show marking criteria
    Rubric: 3 = cannot protect unknown devices, links to CIS; 2 = knowing devices; 1 = vague; 0 = none.
  • EX002 — Spreadsheet columns. List the columns of Leah's device spreadsheet.
    Show marking criteria
    Rubric: 3 = five columns; 2 = four; 1 = fewer; 0 = none.
  • EX003 — Cupboard laptop. What should happen to an unused old laptop?
    Show marking criteria
    Rubric: 3 = wipe and recycle with record; 2 = remove; 1 = keep; 0 = none.
  • EX004 — Five checks. Name the five quick checks.
    Show marking criteria
    Rubric: 3 = all five; 2 = four; 1 = fewer; 0 = none.
  • EX005 — Weakest checks. Which checks scored lowest in the lab?
    Show marking criteria
    Rubric: 3 = encryption and standard user, 8/12; 2 = one; 1 = wrong; 0 = none.
  • EX006 — All-five count. How many laptops passed every check?
    Show marking criteria
    Rubric: 3 = 3 of 12; 2 = three; 1 = wrong; 0 = none.
  • EX007 — Worst laptop. Which laptop did worst and why might that be?
    Show marking criteria
    Rubric: 3 = FB07, old weekend volunteer laptop; 2 = FB07; 1 = wrong; 0 = none.
  • EX008 — Full disk. How can a full disk stop updates?
    Show marking criteria
    Rubric: 3 = no space to download and install; 2 = blocks; 1 = vague; 0 = none.
  • EX009 — Paused updates. What should Leah do about paused updates?
    Show marking criteria
    Rubric: 3 = remove pause, set automatic; 2 = unpause; 1 = vague; 0 = none.
  • EX010 — Other software. Besides Windows, what else needs updating?
    Show marking criteria
    Rubric: 3 = browser and PDF reader with checking; 2 = apps; 1 = vague; 0 = none.
  • EX011 — Restart timing. When should automatic restarts happen at a food bank?
    Show marking criteria
    Rubric: 3 = outside opening hours; 2 = later; 1 = anytime; 0 = none.
  • EX012 — Recording dates. Why write the date beside each check?
    Show marking criteria
    Rubric: 3 = shows when status was true, enables comparison; 2 = tracking; 1 = vague; 0 = none.
  • EX013 — Stolen laptop lesson. What did the stolen laptop reveal about the food bank?
    Show marking criteria
    Rubric: 3 = unknown encryption and contents; 2 = no records; 1 = vague; 0 = none.

Synthesis

In week one, Leah knows every device, has a clear picture of five basics, and has updates working everywhere.

Continue studying — lesson 01 (chapter 01 of 20)

← Course home · Course chapter index · Chapter 02 →

Practice the exercises

Open a prompt, write your response, then compare it with the worked answer. Five-choice practice appears where a reviewed question is available.

EX001

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX002

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Checking for a reviewed five-choice question…

EX003

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Checking for a reviewed five-choice question…

EX004

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX005

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX006

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX007

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX008

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX009

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX010

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX011

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX012

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

EX013

Opens in 30 days: — · browsers: —

Checking for a reviewed five-choice question…

Worked answers

EX001. You cannot protect devices you do not know about; CIS Controls v8 starts with inventory.

EX002. Short name, user, model, serial number and usual location.

EX003. Wipe it securely, recycle it and record that it was disposed of.

EX004. Updates within 14 days, encryption, standard account, screen lock, recent backup.

EX005. Encryption and standard user accounts, eight of twelve each.

EX006. Three of twelve.

EX007. FB07, an old laptop used only by a weekend volunteer.

EX008. Updates need free space to download and install, so they fail.

EX009. Remove the pause and set updates to install automatically.

EX010. The browser, PDF reader and other installed apps.

EX011. Outside opening hours, so nobody loses work during sessions.

EX012. So it is clear when the result was true and later checks can be compared.

EX013. Nobody knew whether it was encrypted or what data it held.