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 malware analysis professionals. The 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 config extraction, beacon parsing, or analyzing suspicious PE files for Cobalt Strike indicators.'
| 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 threat 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 approaches, which is its primary strength. However, it is significantly bloated with explanatory content Claude doesn't need (Key Concepts section, verbose overview, generic 'When to Use'), and the workflow lacks integrated validation checkpoints between steps. The content would benefit from aggressive trimming of explanatory prose and better separation of detailed code into referenced files.
Suggestions
Remove the entire 'Key Concepts' section and 'When to Use' section - Claude already understands these concepts and the code demonstrates them directly.
Trim the overview to 1-2 sentences focusing only on the XOR key values and TLV structure specifics that are genuinely non-obvious.
Add explicit decision points between steps (e.g., 'If Step 1 returns no configs, proceed to Step 2 for manual extraction; if manual extraction also fails, the file may be a stager - extract shellcode first').
Move the YARA rules and network signature generation code into separate referenced files to reduce the main skill's token footprint.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is excessively verbose with unnecessary explanations of concepts Claude already knows (what Cobalt Strike is, what TLV format is, what malleable C2 profiles are). The 'Key Concepts' section is entirely redundant given the code already demonstrates these concepts. The 'When to Use' section is generic filler. The overview paragraph explains basic concepts that don't need explaining to Claude. | 1 / 3 |
Actionability | The skill provides fully executable Python code across all four steps - from config extraction using dissect.cobaltstrike, to manual XOR decryption, YARA rule creation, and network traffic correlation. 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 each has executable code, but there are no explicit validation checkpoints or feedback loops between steps. For example, there's no guidance on what to do if Step 1 fails and when to fall back to Step 2's manual approach, and the 'Validation Criteria' section is a checklist of expected outcomes rather than integrated verification steps within the workflow. | 2 / 3 |
Progressive Disclosure | The content is a monolithic wall of code and text (~250+ lines) that could benefit from splitting the detailed code implementations into separate files. References are provided at the end but the main body contains everything inline. The YARA rules and network correlation code could easily be separate reference files. | 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
888bbe4
- Reviewed
Table of Contents
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