analyzing-cobalt-strike-beacon-configuration
Extract and analyze Cobalt Strike beacon configuration from PE files and memory dumps to identify C2 infrastructure, malleable profiles, and operator tradecraft.
57
66%
Does it follow best practices?
Impact
—
No eval scenarios have been run
Risky
Do not use without reviewing
Optimize this skill with Tessl
npx tessl skill review --optimize ./skills/analyzing-cobalt-strike-beacon-configuration/SKILL.mdQuality
Discovery
82%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a strong, domain-specific description with excellent specificity and natural trigger terms that a security analyst would use. Its main weakness is the absence of an explicit 'Use when...' clause, which would help Claude confidently select this skill in ambiguous situations. The description is concise, uses third person voice correctly, and occupies a very clear niche.
Suggestions
Add an explicit 'Use when...' clause, e.g., 'Use when the user asks about Cobalt Strike beacons, C2 config extraction, beacon parsing, or analyzing suspicious PE files for implant configurations.'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'Extract and analyze beacon configuration', 'identify C2 infrastructure, malleable profiles, and operator tradecraft' from specific input types 'PE files and memory dumps'. | 3 / 3 |
Completeness | Clearly answers 'what does this do' (extract and analyze beacon config, identify C2/malleable profiles/tradecraft), but lacks an explicit 'Use when...' clause specifying when Claude should select this skill. The 'when' is only implied by the domain context. | 2 / 3 |
Trigger Term Quality | Includes highly relevant natural keywords a user would say: 'Cobalt Strike', 'beacon', 'C2 infrastructure', 'malleable profiles', 'PE files', 'memory dumps', 'operator tradecraft'. These are the exact terms a threat analyst or incident responder would use. | 3 / 3 |
Distinctiveness Conflict Risk | Extremely distinct niche — Cobalt Strike beacon analysis is a very specific cybersecurity/threat intelligence domain. Unlikely to conflict with any other skill due to the highly specialized terminology and use case. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
50%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
The skill provides strong, executable code for Cobalt Strike beacon analysis across multiple techniques, which is its primary strength. However, it is significantly bloated with explanatory content Claude already knows (what Cobalt Strike is, what TLV means, what malleable profiles are), and the workflow lacks integrated validation checkpoints between steps. The monolithic structure would benefit from splitting detailed code into separate files with a concise overview in SKILL.md.
Suggestions
Remove or drastically reduce the 'Overview', 'When to Use', 'Key Concepts', and 'Prerequisites' sections—Claude knows what Cobalt Strike is and how XOR encoding works. Keep only the XOR key values (0x69/0x2e) and TLV format specifics as quick-reference notes.
Add explicit validation checkpoints between workflow steps, e.g., 'Verify config extraction succeeded before proceeding to manual decryption' and 'If YARA scan finds no matches, check if sample is packed and retry after unpacking.'
Split the large code blocks into separate bundle files (e.g., extract_config.py, manual_decrypt.py, yara_rules.py, c2_analysis.py) and reference them from SKILL.md with brief descriptions of when to use each.
Integrate the 'Validation Criteria' items as inline checkpoints within each workflow step rather than listing them as a separate section at the end.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is excessively verbose. The 'Overview' section explains what Cobalt Strike is and how beacons work—knowledge Claude already has. The 'When to Use' section is generic boilerplate. The 'Key Concepts' section rehashes well-known malware analysis concepts. The 'Prerequisites' section lists obvious tools. Much of this could be cut to focus on the actual extraction code and workflow. | 1 / 3 |
Actionability | The skill provides fully executable Python code for config extraction, manual XOR decryption, YARA rule scanning, and C2 profile analysis. Code is complete with imports, function definitions, and main blocks—copy-paste ready for an analyst. | 3 / 3 |
Workflow Clarity | Steps are numbered and sequenced (extract → manual decrypt → YARA scan → network correlation), but there are no explicit validation checkpoints or error recovery loops between steps. The 'Validation Criteria' section is a checklist at the end rather than integrated feedback loops. For a workflow involving potentially corrupted/packed samples, missing validation between steps is a gap. | 2 / 3 |
Progressive Disclosure | The content is a monolithic wall of text with all code inline. The extensive code blocks for manual XOR decryption, YARA rules, and network analysis could be split into separate referenced files. References section exists but only links to external resources, not internal bundle files for organization. | 2 / 3 |
Total | 8 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
- Repository
- mukul975/Anthropic-Cybersecurity-Skills
- Commit
0445030
- Reviewed
Table of Contents
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