BC performing-malware-triage-with-yara
Performs rapid malware triage and classification using YARA rules that match file patterns, strings, byte sequences, and structural characteristics against known malware families and suspicious indicators, covering rule writing, scanning, and integration into analysis pipelines. Use when classifying a batch of malware samples against known family signatures, writing detection rules for a newly analyzed malware family, or performing signature-based malware triage.
Performs rapid malware triage and classification using YARA rules that match file patterns, strings, byte sequences, and structural characteristics against…
As a process C 63/100 · Has gaps — weak spots: failures and branches, running it twice, progress reporting
How to improve
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 3
✓ No critical or high findings
Medium and low: 3
-
low Risky intent
intent-offensive-securitySKILL.md:93Offensive-security / dual-use content (legitimate for authorised testing; review intended use) (detector / deny-list definition)Create YARA rules based on strings extracted during malware analysis:
detector -
low Risky intent
intent-offensive-securitySKILL.md:230Offensive-security / dual-use content (legitimate for authorised testing; review intended use) (detector / deny-list definition)"ransomware": "rules/ransomware_rules.yar",
detector -
low Risky intent
intent-offensive-securitySKILL.md:357Offensive-security / dual-use content (legitimate for authorised testing; review intended use)Ransomware: 187 samples (7.5%)
Files scanned: 4. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- note
frontmatter-keyunknown frontmatter key "domain" - note
frontmatter-keyunknown frontmatter key "subdomain" - note
frontmatter-keyunknown frontmatter key "nist_csf" - note
frontmatter-keyunknown frontmatter key "mitre_attack"
Process rating: all ten parameters 63/100
- 0Failures and branches. Linear process with no failure handling
- 0Progress reporting. Says nothing while it works
- 30Running it twice. 5 mutating operations with no state check
- 50When it triggers. No condition that starts the skill
- 60Tools and files. Uses tools (python) that frontmatter does not declare
- 60Result and completion. Output format stated, no completion criterion
- 70Inputs and preconditions. Inputs and preconditions are listed
- 100Steps. 26 steps
- 100Consistency. Name and required fields are in place
- 100Execution cost. Instruction body is 2944 tokens
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +5Description has no quoted example phrases that should trigger the skill
- -41 reference files, but SKILL.md never points to them: the model will not open them
- -31 of 1 scripts are never mentioned in SKILL.md
- +2Single-language instructions
- +4Description says when NOT to use the skill
- +3Description length 467: enough signal without eating the budget
- +4Structure: 15 headings
- +3Step-by-step instructions: 26 items
- +3Output format is stated explicitly
- +4Has examples (8 code blocks)
- +1License stated
Quality base 70; lint remarks subtract, signals add up to 100. Result: 82.