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.
68
82%
Does it follow best practices?
Impact
—
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 an excellent skill description that clearly defines a specific cybersecurity niche. It provides concrete actions, covers relevant protocol types, states the purpose of the analysis, and includes an explicit activation clause with natural trigger terms. The description is concise yet comprehensive, making it easy for Claude to distinguish this skill from other security-related skills.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: analyzing beacon patterns, command structures, data encoding, infrastructure mapping. Also specifies protocol types (HTTP, HTTPS, DNS, custom) and output purposes (detection development, threat intelligence). | 3 / 3 |
Completeness | Clearly answers both 'what' (analyzes C2 communication protocols covering beacon patterns, command structures, data encoding, infrastructure across multiple protocol types) 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', 'beacon detection'. These cover common variations a security analyst would use. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche focused specifically on malware C2 communication analysis. The domain is narrow enough (C2 protocols, beacon patterns, infrastructure mapping) that it's unlikely to conflict with general networking, malware analysis, or other security skills. | 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 with executable code examples covering the full C2 analysis workflow from beacon detection through signature creation. Its main weaknesses are verbosity (explaining concepts Claude already knows, like what Wireshark is or what beaconing means), lack of explicit validation checkpoints between workflow steps, and a monolithic structure that would benefit from splitting reference material into separate files.
Suggestions
Remove or drastically trim the Key Concepts glossary table and Tools & Systems section—Claude already knows what beaconing, jitter, domain fronting, and Wireshark are
Add explicit validation checkpoints between workflow steps, e.g., 'Verify beacon detection results by manually inspecting 2-3 flagged connections in Wireshark before proceeding' and 'Test Suricata rules against the original PCAP to confirm they trigger'
Split the C2 framework signatures reference, Suricata rule templates, and output format template into separate bundle files to reduce the main skill's token footprint
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is fairly comprehensive but includes some unnecessary verbosity, such as the full C2 channel type descriptions (Claude knows what DNS tunneling and ICMP are), the glossary table explaining basic concepts like 'beaconing' and 'jitter', and the tools section describing what Wireshark does. The reference tables for C2 frameworks are useful but could be tighter. | 2 / 3 |
Actionability | The skill provides fully executable Python scripts for beacon analysis, protocol decoding, and infrastructure enrichment, plus complete Suricata detection rules. Code examples use real libraries (scapy, dpkt, cobalt_strike_parser) with proper imports and are copy-paste ready. | 3 / 3 |
Workflow Clarity | The six-step workflow is clearly sequenced and logically ordered from identification through detection signature creation. However, there are no explicit validation checkpoints or feedback loops between steps—for example, no verification that beacon detection results are accurate before proceeding to protocol decoding, and no validation step after creating Suricata rules to confirm they fire correctly. | 2 / 3 |
Progressive Disclosure | The content is a monolithic document with no references to supporting files. At ~300 lines, the C2 framework signatures table, infrastructure mapping code, and detailed output format template could be split into separate reference files. The scenario section and glossary add bulk that would be better as linked resources. | 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
0f429d0
- Reviewed
Table of Contents
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