analyzing-macro-malware-in-office-documents

Analyzes malicious VBA macros embedded in Microsoft Office documents (Word, Excel, PowerPoint) to identify download cradles, payload execution, persistence mechanisms, and anti-analysis techniques. Uses olevba, oledump, and VBA deobfuscation to extract the attack chain. Activates for requests involving Office macro analysis, VBA malware investigation, maldoc analysis, or document-based threat examination.

Quality

84%

Does it follow best practices?

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Securityby

Low

Low-risk findings worth noting

Quality

Content

68%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The content is highly actionable with concrete, executable tooling at every step and a clear six-step workflow. Its weaknesses are moderate verbosity from inline reference material and a missing validation/feedback-loop checkpoint given the destructive nature of live maldoc analysis.

Suggestions

Add explicit validation checkpoints to the workflow (e.g., verify triage output indicates macros before extraction; confirm deobfuscation produced a coherent payload before reporting), since analyzing live maldocs is a destructive/risky operation.

Move the inline Python deobfuscation function and DDE/relationship inspection scripts into scripts/ or references/api-reference.md, linking from the body to reduce token load and improve progressive disclosure.

Trim the Key Concepts glossary entries that restate well-known concepts (what VBA, OLE, DDE are) and keep only the attack-specific distinctions Claude would not already infer.

Dimension	Reasoning	Score
Conciseness	The body is mostly efficient with executable commands, but the inline Python deobfuscation snippet, the multi-line DDE/relationship Python blocks, and the Key Concepts table partly re-explain concepts (VBA, DDE, OLE) Claude already knows, adding length that could be offloaded to references/api-reference.md.	3 / 5
Actionability	Provides copy-paste-ready commands at every step (olevba, oledump.py with specific flags, xlmdeobfuscator) and a complete executable deobfuscate_vba Python function, covering the common analysis cases concretely.	5 / 5
Workflow Clarity	The six-step sequence is clearly ordered, but this skill involves batch/destructive-adjacent operations (executing extracted macro logic, analyzing live maldocs) with no explicit validation or verify-retry checkpoints between steps; per the destructive/batch cap, workflow clarity is capped at 3.	3 / 5
Progressive Disclosure	Good overall structure with sections for triage, extraction, deobfuscation, XLM, non-macro vectors, and reporting, plus a real references/api-reference.md and scripts/agent.py bundle; however the body inlines substantial reference-style material (full code blocks, Key Concepts glossary) rather than linking to those bundle files, so it is not fully one-level-deep.	4 / 5
	Total	15 / 20 Passed

Description

100%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description is specific, complete, and well-triggered: it states concrete actions, names tools, and gives explicit 'use when' guidance with natural synonyms. It is a strong, low-conflict description.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete actions — 'identify download cradles, payload execution, persistence mechanisms, and anti-analysis techniques' — and names specific tools (olevba, oledump), giving comprehensive coverage of capabilities.	5 / 5
Completeness	Clearly states both what the skill does (analyze malicious VBA macros, extract the attack chain) and when to use it ('Activates for requests involving Office macro analysis, VBA malware investigation, maldoc analysis, or document-based threat examination'), with concrete trigger phrases.	5 / 5
Trigger Term Quality	Includes natural user phrases and variations — 'Office macro analysis,' 'VBA malware investigation,' 'maldoc analysis,' 'document-based threat examination' — covering synonyms a user would actually say.	5 / 5
Distinctiveness Conflict Risk	The niche is sharply scoped to malicious Office macro/VBA analysis with distinct trigger terms, making it unlikely to fire for unrelated malware-analysis or general document skills.	5 / 5
	Total	20 / 20 Passed

Validation

93%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	15 / 16 Passed

Repository: mukul975/Anthropic-Cybersecurity-Skills
Path: skills/analyzing-macro-malware-in-office-documents/SKILL.md
Commit: 9429fe9

Reviewed: 2 days ago

Table of Contents

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