Lab — YARA — Malware Analysis with AI

Visual · mal_yara_lab

Lab: write YARA pack. $MAL_LAB only. Original Cyberlium.

YARA pack before production handoff — anatomy and FP testing on paper first.

Lessons 5-1 through 5-3 covered YARA naming, rule anatomy, and false positives. This lab merges them into one YARA literacy pack for $MAL_LAB linked to M4 IOC strings. Optional: draft rule skeleton using placeholder strings from public report — no live sample required. No unauthorized scanning. Next: Quiz — YARA Literacy.

1. Lab contract: write the YARA pack

Create $HOME/cyberlium-lab/t22-m05-l04-yara-lab.txt merging use cases, rule skeleton, FP checklist, and link to M4 strings/hash pack.

Optional: yara rule.yar on static copy of legal training sample in $MAL_LAB — if infra available.

Command guide

Try these commands — Lab contract: write the YARA pack

═══ LINUX / macOS / WINDOWS (YARA Analysis) ═══

Create a sample detection rule for suspicious downloader artifacts

Command — copy this

cat << 'EOF' > detect_suspicious.yar
rule Suspicious_Downloader_Artifact {
    meta:
        description = "Detects PowerShell web download patterns and executable headers"
        author = "Cyberlium SOC Analyst"
        date = "2026"
    strings:
        $mz = { 4D 5A }
        $s1 = "DownloadString" nocase
        $s2 = "WebClient" nocase
        $s3 = "powershell -enc" nocase
    condition:
        $mz at 0 and (any of ($s*))
}
EOF

Compile and validate the YARA rule against a file or folder

Command — copy this

yara -w detect_suspicious.yar /path/to/sample.bin

Primary tools to practice this lesson: yara, strings. Reference sites: YARA performance (https://yara.readthedocs.io/en/stable/writingrules.html); ANY.RUN YARA hits (https://any.run/); VirusTotal YARA (https://www.virustotal.com/). Run every command in the box — install first, then the usage lines — only on YOUR lab / program scope.

2. Cross-check offensive YARA misuse

Grep for FUD, evasion, unauthorized scan language — delete. Tutorials teaching AV bypass get rewritten to defender detection skeleton only.

Classmates write their own YARA packs for their $MAL_LAB.

3. Lock the proof

chmod 600 on the pack. Quiz next — then Dynamic Analysis Basics.

YARA literacy feeds dynamic sandbox module — static rules plus behavior.

4. What you ship: YARA literacy pack for $MAL_LAB

Use cases + rule skeleton + FP checklist merged. $MAL_LAB named. No evasion offense. chmod 600.

5. What you record before the next lesson

Date. YARA pack path. $MAL_LAB named. File t22-m05-l04-yara-lab.txt chmod 600.

6. Wrong vs right: live malware on daily driver vs sandbox

Worked failure — same MSF word, opposite target. Right never needs a café Wi-Fi or classmate laptop.

Wrong: Add AV evasion rule to pack. Scan production without authorization.
Right: Write YOUR YARA literacy pack for $MAL_LAB. chmod 600. Next: Quiz — YARA Literacy.

Hands-on Exercise

Mission: freeze YOUR YARA pack on disk

1) Merge M5 literacy sections. 2) Link M4 strings/hash pack. 3) chmod 600. Never include evasion or unauthorized scan steps.

Pro Tip

Stuck? Ask Cyberlium AI Mentor

YARA packs bridge static IOCs and detection engineering.

Practice QuizQuestion 1

Multiple choice

APPLY: This lab requires:

Practice QuizQuestion 2

True or False

APPLY: True or False: YARA pack should include FP test checklist.

Practice QuizQuestion 3

Multiple choice

APPLY: Rule skeleton meta should include: