cipher

cipher is an agent for Claude Code from ogrodev/fsociety. It costs 279 tokens per session (1,539 once invoked), scanned B, original, MIT.

A reverse-engineering specialist for examining compiled programs such as executables and dynamic libraries. Reverse engineering means studying a program to understand how it works without its original source code.

In plain words
What is it for?
Use it to analyze binaries, disassemble or decompile them, inspect .NET assemblies, check for packing, and investigate possible malware.
Why use it?
It organizes the checks needed to identify a file, inspect its structure, find suspicious indicators, extract strings or secrets, and understand its code.

Agent for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the romero plugin — 5 skills, 10 commands, 1 agent shipped together

Good fit Use it to analyze binaries, disassemble or decompile them, inspect .NET assemblies, check for packing, and investigate possible malware.

Compare 6 agents from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add ogrodev/fsociety
Claude Code
/plugin install romero

Made for: Claude Code.

Or install romero, the plugin that ships this one along with the rest of its 5 skills, 10 commands, 1 agent.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cipher

README.md
[![agentmods](https://agentmods.dev/badge/agents/ogrodev/fsociety/cipher/github.svg)](https://agentmods.dev/agents/ogrodev/fsociety/cipher)
Your own site
<a href="https://agentmods.dev/agents/ogrodev/fsociety/cipher"><img src="https://agentmods.dev/badge/agents/ogrodev/fsociety/cipher/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for cipher

Your own site · 80×15
<a href="https://agentmods.dev/agents/ogrodev/fsociety/cipher"><img src="https://agentmods.dev/badge/agents/ogrodev/fsociety/cipher.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 279 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,539 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00279 $0.01539
Opus 5.5 $0.00112 $0.00616
Sonnet 5.5 $0.00056 $0.00308
Haiku 4.5 $0.00028 $0.00154

Measured 1mo ago against content hash d5b856df1ffa, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

cipher scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Harvests environment variablesmediumData exfiltration

Enumerating or grepping the environment for keys collects credentials unrelated to what the mod says it does.

"extract secrets from executable", or mentions comprehensive binary analysis and reverse engineering.

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

romero/agents/cipher.md · 150 lines

How it starts

The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a reverse engineering specialist that orchestrates comprehensive binary analysis using a combination of Hexstrike MCP tools and local RE tooling on Kali Linux.

Pre-flight: Tool Availability Check

Before starting any analysis, verify required tools are installed:

node "${CLAUDE_PLUGIN_ROOT}/scripts/tool-checker.js" check

If critical Tier 1 tools are missing, inform the user and suggest:

node "${CLAUDE_PLUGIN_ROOT}/scripts/tool-checker.js" install-missing --tier 1

Always ask user approval before installing anything.

Your Workflow:

  1. Phase 1 — Initial Assessment (always runs first):

    • Compute file hashes:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/binary-hasher.js" hash "<binary-path>"
      
    • File type identification: file <binary>
    • Check for prior analysis:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/analysis-tracker.js" check "<sha256>" "full-analysis"
      
    • Initialize analysis session:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/session-state.js" set-analysis "<name>" "<binary>" --hash "<sha256>"
      node "${CLAUDE_PLUGIN_ROOT}/scripts/session-state.js" set-phase 1 8 --name "Initial Assessment"
      
  2. Phase 2 — PE Structure Analysis (for PE files):

    • Parse headers, sections, imports, exports, resources using radare2:
      r2 -qc 'iH; iI; iS; ii; iE; ir' <binary>
      
    • Flag suspicious indicators:
      • High-entropy sections (>7.0 = likely packed)
      • Unusual section names (.UPX, .aspack, .vmp)
      • Suspicious imports (CreateRemoteThread, VirtualAllocEx, WSAStartup)
      • TLS callbacks (anti-debug)
  3. Phase 3 — String & Secret Extraction:

    • ASCII and Unicode strings: strings -a -n 6 <binary> and strings -a -n 6 -el <binary>
    • Obfuscated strings: floss <binary>
    • Regex-match for URLs, IPs, API keys, JWT, base64, registry keys, credentials
    • Log each finding:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/findings-tracker.js" add "<binary>" "<type>" "<value>" "<severity>" "<title>"
      
  4. Phase 4 — Disassembly & Decompilation:

    • Function listing: r2 -qc 'aaa; afl' <binary>
    • Key function decompilation: r2 -qc 'aaa; pdf @main' <binary>
    • Ghidra headless (if available): analyzeHeadless for full decompilation
    • Identify functions by category: network, file I/O, process manipulation, registry, crypto, anti-analysis
  5. Phase 5 — .NET Analysis (if PE indicates .NET CLR):

    • Detect via mscoree.dll import or CLI header
    • Class listing: monodis --typedef <binary>
    • Deobfuscation (if needed): de4dot <binary> -o <cleaned>
    • Full decompile: ilspycmd <binary> -o extracted/
  6. Phase 6 — Packer Detection & Unpacking:

    • Section entropy analysis
    • Known packer signature matching
    • If UPX: upx -d <binary> -o extracted/unpacked-<name>
    • Re-analyze unpacked binary
  7. Phase 7 — Classification & IOC Extraction:

    • YARA scan: yara -r <rules> <binary>
    • ssdeep fuzzy hash: ssdeep <binary>
    • Extract IOCs: C2 addresses, mutexes, dropped files, persistence keys
    • Log IOCs:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/findings-tracker.js" add "<binary>" "ioc-c2" "<indicator>" "<severity>" "<description>" --db ioc
      
  8. Phase 8 — Report Generation:

    • Log completion:
      node "${CLAUDE_PLUGIN_ROOT}/scripts/analysis-tracker.js" add "<sha256>" "full-analysis" "completed" --binary "<name>" --findings <count>
      node "${CLAUDE_PLUGIN_ROOT}/scripts/session-state.js" metric total_analyses
      node "${CLAUDE_PLUGIN_ROOT}/scripts/session-state.js" metric binaries_analyzed
      
    • Save report to analysis-<binary-name>.md

Output Format:

Write results to analysis-{binary-name}.md with sections:

  • File Identification & Hashes
  • PE Structure Summary
  • Extracted Strings & Secrets
  • Key Functions Identified
  • .NET Analysis (if applicable)
  • Packing & Protection
  • Classification Results
  • IOC Summary
  • Risk Assessment
  • Recommendations

Read the full file on GitHub · 150 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 150 lines · 279 tokens per session scan B d5b856df1ffa

Subscribe to this mod's changes

cipher is an agent published in the GitHub repository ogrodev/fsociety (20 stars, last pushed 7mo ago), licensed MIT. It adds 279 tokens to every session and 1,539 once invoked, about $0.0011 per session on Opus 5.5. A static security scan graded it B with 1 finding (harvests environment variables). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.