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.
72
66%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Critical
Do not install 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 trigger term coverage for threat intelligence and malware analysis workflows. Its main weakness is the absence of an explicit 'Use when...' clause, which would help Claude know precisely when to select this skill. The technical terminology is appropriate for the target audience and creates a highly distinctive skill profile.
Suggestions
Add an explicit 'Use when...' clause, e.g., 'Use when the user asks about Cobalt Strike beacons, C2 analysis, beacon config extraction, or malware implant analysis from PE files or memory dumps.'
| 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 Cobalt Strike beacon config to identify C2 infrastructure, malleable profiles, tradecraft), but lacks an explicit 'Use when...' clause or equivalent trigger guidance, which caps this at 2 per the rubric. | 2 / 3 |
Trigger Term Quality | Excellent coverage of natural terms a security analyst would use: 'Cobalt Strike', 'beacon', 'configuration', 'PE files', 'memory dumps', 'C2 infrastructure', 'malleable profiles', 'operator tradecraft'. These are highly specific domain terms that users in this field would naturally mention. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche focused specifically on Cobalt Strike beacon analysis. The combination of 'Cobalt Strike', 'beacon configuration', 'malleable profiles', and 'C2 infrastructure' creates a very clear and unique domain that is unlikely to conflict with other skills. | 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 highly actionable, executable Python 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 C2 profiles are), and the workflow lacks explicit validation checkpoints and fallback guidance between steps. The monolithic structure would benefit from splitting detailed code into referenced files.
Suggestions
Remove the 'Key Concepts' section and 'Overview' explanatory paragraphs—Claude already understands Cobalt Strike, TLV encoding, and malleable C2 profiles. Keep only the XOR key values (0x69/0x2e) and config offset details as inline comments in the code.
Add explicit validation checkpoints between steps: e.g., 'If Step 1 returns no config, proceed to Step 2 for manual extraction' and 'Verify extracted C2 domains resolve before generating network signatures.'
Move the large code blocks into referenced files (e.g., `extract_config.py`, `beacon_yara.yar`, `c2_analysis.py`) and keep SKILL.md as a concise overview with usage examples and navigation links.
Remove the generic 'When to Use' section—it adds no actionable information beyond what the skill title already conveys.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is excessively verbose. The 'Overview' section explains what Cobalt Strike is (Claude knows this), the 'Key Concepts' section re-explains TLV format and malleable C2 profiles that are already covered in the code, and the 'When to Use' section is generic boilerplate. The Prerequisites section lists obvious tools. Much of this content is redundant with the code examples themselves. | 1 / 3 |
Actionability | The skill provides fully executable Python code across all four steps—config extraction using dissect.cobaltstrike, manual XOR decryption with TLV parsing, YARA rule compilation and scanning, and network signature generation. Code is copy-paste ready with proper imports, function definitions, and CLI entry points. | 3 / 3 |
Workflow Clarity | The four steps are clearly sequenced and logically ordered (extract → manual decrypt → detect → correlate). However, there are no explicit validation checkpoints or feedback loops between steps—e.g., no guidance on what to do if Step 1 fails and when to fall back to Step 2's manual approach, or how to verify extracted config integrity before proceeding to network correlation. | 2 / 3 |
Progressive Disclosure | The content is a monolithic wall of text with ~300 lines of inline code that could benefit from being split into separate files (e.g., extraction script, YARA rules, network analysis). References are listed at the bottom but the main body doesn't use progressive disclosure—everything is dumped inline rather than having a concise overview pointing to detailed materials. | 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
c15f73d
- Reviewed
Table of Contents
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