Purple › Module 9 › Lesson 1
Purple Findings
Purple findings literacy — detection miss, rule gap, telemetry gap, tuning need — structured finding rows on YOUR `$PURPLE_LAB` exercises.
Visual · t35_purple_findings
Purple findings = named finding rows. $PURPLE_LAB. Original Cyberlium.
Opening
Purple work produces findings — name structured detection and coverage findings on YOUR lab before vague 'we need better SIEM' notes.
Purple findings literacy names: finding ID category, ATT&CK technique link category, detection miss or gap category, evidence stub category (atomic UTC, log snippet literacy), and severity/priority category. Analyst documents purple finding register on `$PURPLE_LAB` — three findings from Modules 6–8 exercises with technique link, honest evidence, priority — without blame-focused red vs blue attacks, without hiding negative results, without prod finding tickets from unauthorized lab notes. Cyberlium teaches professional finding vocabulary — YOUR notes. Refused: blame theater, fabricated findings, unauthorized prod tickets. Lab row: purple finding register (three findings, technique link, evidence stub, priority).
1. Named finding rows
Finding ID, technique link, gap type, evidence stub, priority — five literacy anchors.
Evidence cites lab atomic UTC or log replay — not speculation.
Command guide
Try these commands — Named finding rows
═══ TOOLS & WEBSITES ═══ Browse / read these (authorized learning only — stay in YOUR lab / program scope)
MITRE ATT&CK — https://attack.mitre.org/ Elastic detection — https://www.elastic.co/guide/en/security/current/rules-ui.html Sigma — https://sigmahq.io/
═══ INSTALL ═══
Linux (Debian/Ubuntu):
Command — copy this
sudo apt install python3
macOS:
Command — copy this
brew install python3
Windows: Download https://python.org/downloads/
═══ LINUX / macOS ═══
Command — copy this
export PURPLE_LAB=${PURPLE_LAB:-$HOME/cyberlium-lab/t35-purple}
cat > "$PURPLE_LAB/findings/purple-findings-template.md" <<'EOF'
# Purple Finding — YOUR template
- **ID:** PURPLE-FND-001
- **Exercise:** PURPLE-LAB-001
- **Technique:** T1110.001
- **Detection rule:** failed-logon-lab.yml
- **Result:** fired on jq replay (3x4625 → 4624 jsmith)
- **Severity:** medium (lab)
- **Recommendation:** add time window + count threshold to reduce FP
- **Owner:** detection engineering
- **Due:** +14d
Finding types: detection gap | noisy rule | telemetry gap | tuning needed
EOFCommand — copy this
grep -E 'PURPLE-FND|T1110|Recommendation|failed-logon' "$PURPLE_LAB/findings/purple-findings-template.md"
Primary tools to practice this lesson: grep, python3. Reference sites: MITRE ATT&CK (https://attack.mitre.org/); Elastic detection (https://www.elastic.co/guide/en/security/current/rules-ui.html); Sigma (https://sigmahq.io/). Run every command in the box — install first, then the usage lines — only on YOUR lab / program scope.
2. Blameless discipline
Findings document system gaps — not red vs blue personal blame.
Link Module 8 gap register — same coverage thread.
3. Refused
No blame theater; no fabricated findings; no unauthorized prod tickets from lab.
Finding literacy supports improvement — not scapegoating.
4. What you ship: purple finding register
Three findings + technique link + evidence stub + priority + NEVER blame theater line.
5. What you record before the next lesson
Purple finding register path.
6. Wrong vs right: stranger networks vs YOUR purple lab
Worked failure — same MSF word, opposite target. Right never needs a café Wi-Fi or classmate laptop.
Wrong
Write finding doc blaming blue team personally for detection miss from lab exercise.
Right
Purple finding register from `$PURPLE_LAB` exercises. Next: Blue Backlog.
Mission: purple finding register
1) Name five finding literacy rows. 2) Three findings from Modules 6–8. 3) Evidence stub and priority each. 4) Write NEVER blame theater line.
Stuck? Ask Cyberlium AI Mentor
Ask Mentor: “Finding ID — literacy format stub?”
Knowledge Check
APPLY: Purple findings literacy uses:
Multiple choice
Knowledge Check
APPLY: True or False: Blame theater belongs in purple findings.
True or False
Knowledge Check
APPLY: Finding register includes:
Multiple choice