analyzing-command-and-control-communication
Analyzes malware command-and-control (C2) communication protocols to understand beacon patterns, command structures, data encoding, and infrastructure. Covers HTTP, HTTPS, DNS, and custom protocol C2 analysis for detection development and threat intelligence. Activates for requests involving C2 analysis, beacon detection, C2 protocol reverse engineering, or command-and-control infrastructure mapping.
85
82%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Advisory
Suggest reviewing before use
Quality
Discovery
100%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 skill description that clearly defines a specific cybersecurity niche—C2 protocol analysis—with concrete actions, relevant protocol types, and explicit trigger conditions. It uses proper third-person voice, includes natural keywords that security analysts would use, and has a clear 'Activates for...' clause that serves as an explicit trigger guide. The description is concise yet comprehensive.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: analyzing beacon patterns, command structures, data encoding, infrastructure mapping, and detection development. Also specifies protocol types (HTTP, HTTPS, DNS, custom). | 3 / 3 |
Completeness | Clearly answers both what ('Analyzes malware C2 communication protocols to understand beacon patterns, command structures, data encoding, and infrastructure') and when ('Activates for requests involving C2 analysis, beacon detection, C2 protocol reverse engineering, or command-and-control infrastructure mapping'). | 3 / 3 |
Trigger Term Quality | Includes strong natural trigger terms users would say: 'C2', 'command-and-control', 'beacon', 'C2 protocol', 'reverse engineering', 'infrastructure mapping', 'detection development', 'threat intelligence'. Good coverage of both abbreviated and full forms. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche focused specifically on C2/command-and-control protocol analysis. Unlikely to conflict with general malware analysis or network security skills due to the specific focus on C2 communication patterns and beacon detection. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
64%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a thorough and highly actionable skill for C2 analysis with excellent executable code examples and realistic detection signatures. Its main weaknesses are length/verbosity (glossary of known terms, extensive channel listing) and lack of explicit validation checkpoints in the workflow. The content would benefit from splitting detailed reference material into separate files and adding verification steps between workflow stages.
Suggestions
Add explicit validation checkpoints between workflow steps, e.g., 'Verify beacon detection by checking at least 3 intervals match before proceeding to protocol analysis' and 'Test Suricata rules against the original PCAP to confirm detection before deployment'.
Move the Key Concepts glossary table and the Known C2 Framework Signatures reference block into separate linked files (e.g., FRAMEWORKS.md, GLOSSARY.md) to reduce the main skill's token footprint.
Remove or significantly trim explanatory text that Claude already knows, such as the descriptions of what each C2 channel type is (HTTP, DNS, ICMP) — keep only the specific indicators.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is fairly comprehensive but includes some unnecessary verbosity, particularly the Key Concepts glossary table which explains terms Claude already knows (beaconing, jitter, domain fronting). The C2 channel identification table in Step 1 is somewhat redundant for Claude. However, the code examples and framework signatures earn their place. | 2 / 3 |
Actionability | Provides fully executable Python scripts for beacon analysis, protocol decoding, and infrastructure mapping. Includes complete Suricata detection rules that are copy-paste ready. The code uses real libraries (scapy, dpkt, cobalt_strike_parser) with proper imports and realistic logic. | 3 / 3 |
Workflow Clarity | The 6-step workflow is clearly sequenced and logically ordered from identification through detection creation. However, there are no explicit validation checkpoints or feedback loops between steps — for instance, no verification that beacon detection is accurate before proceeding to infrastructure mapping, and no validation step after creating detection signatures to confirm they match the observed traffic. | 2 / 3 |
Progressive Disclosure | The content is a long monolithic document (~250+ lines) with no references to external files for detailed content like the framework signatures catalog, the full command set documentation, or extended code examples. The scenario section and tools list could be split out. However, the section headers provide reasonable internal navigation. | 2 / 3 |
Total | 9 / 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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