防病毒技术白皮书

目录 1概述·······················································································································································1-11.1技术背景············································································································································1-11.2技术特点············································································································································1-12防病毒技术实现····································································································································2-12.1概念介绍············································································································································2-12.1.1防病毒特征与特征库···············································································································2-12.1.2 MD5规则································································································································2-22.1.3防病毒动作······························································································································2-22.1.4防病毒例外······························································································································2-22.1.5云端服务器······························································································································2-32.1.6智能业务平台··························································································································2-32.1.7文件引擎·································································································································2-42.2技术实现············································································································································2-42.2.1病毒检测整体流程···················································································································2-42.2.2本地特征库快速检测···············································································································2-62.2.3云端服务器协同检测···············································································································2-82.2.4智能业务平台增强检测···········································································································2-92.2.5文件引擎深度检测·················································································································2-122.3技术对比··········································································································································2-132.3.1防病毒与APT防御技术的对比·····························································································2-133典型组网应用······································································································································3-143.1边界部署，阻断病毒入侵·················································································································3-14 1概述 1.1技术背景 随着数字化进程的加速，计算机系统和网络面临着日益复杂的恶意代码威胁。从传统的病毒、蠕虫到高级持续性威胁（APT），这些恶意程序通过多种渗透途径进入计算机系统，不仅威胁个人隐私和数据完整性，更可能引发系统瘫痪和网络攻击扩散，给企业内网安全带来严峻挑战。在此背景下，防病毒技术作为关键防护手段不断发展演进。 防病毒技术作为网络安全的基础防线，经历了从简单特征识别到智能协同防御的重大技术变革。早期基于特征码匹配的静态检测技术，虽能有效应对已知威胁，却难以防范零日漏洞利用、多态病毒等新型攻击方式。现代防病毒体系通过本地引擎毫秒级特征匹配、云端智能分析、智能业务平台静态解析与动态行为建模、文件引擎深度内容检测、沙箱虚拟环境深度分析以及全球威胁情报网络协同防护的多层联动机制，构建了全方位的智能协同防御体系。 1.2技术特点 防病毒具有如下技术特点： •深度防护：可对网络数据流进行协议分析和重组，对报文的应用层内容进行详细分析，识别出隐藏病毒特征，提高病毒检测的准确性。•全面防护：支持对已知病毒与未知威胁的双重防护，覆盖文件、内存、网络等多个层面的保护。•庞大且持续更新的特征库：内置专业病毒特征库，定期自动升级，确保能够及时响应新出现的病毒变种与攻击手法。•云端协同防护：通过与云端服务器联动，利用云端强大的计算资源与海量病毒数据库，实现对可疑文件的远程鉴定，弥补本地检测盲区。•智能分析检测：结合智能业务平台提供的机器学习与人工智能算法，对可疑文件进行脱壳、行为模拟与模式识别，提升对混淆、加密、变形病毒的检出率。•文件深度识别：支持对加密压缩包、嵌套文档、Office宏等复杂结构文件的内容提取与扫描，穿透多层封装，发现深层威胁。 2防病毒技术实现 2.1概念介绍 2.1.1防病毒特征与特征库 1.防病毒特征 防病毒特征是设备用于识别应用层信息中是否携带病毒的关键字符串，由系统内置的病毒特征库预定义。每个特征代表一种特定病毒的行为或代码片段，通常以唯一的病毒ID标识。 2.防病毒特征库 防病毒特征库是由专业安全研究人员通过对大量真实病毒样本进行逆向分析后构建的权威数据库。库中每一条特征均精确描述了某种病毒在网络传输过程中的典型表现，如特定的二进制序列、HTTP请求头异常字段、PE文件节区命名规律等。 防病毒特征库作为一个持续更新的资源库，是网络安全防御的关键组成部分。不仅能识别和防御当前已知的病毒，还能通过定期的更新迅速适应新出现的病毒。这确保了企业和组织能够在不断变化的网络威胁环境中保持防御的先进性和有效性。 防病毒特征库升级 为保障防护能力始终处于前沿水平，防病毒特征库支持多种升级方式： •定期自动在线升级：按照设定周期（如每日凌晨）自动从官网获取最新版本特征库并加载到设备本地，更新本地的防病毒特征库。•立即自动在线升级：管理员手动触发设备即时获取官网最新版本特征库文件，立即更新本地的防病毒特征库。•手动离线升级：当设备无法自动获取防病毒特征库时，需要管理员先手动获取最新的防病毒特征库，再更新设备本地的防病毒特征库。 防病毒特征库回滚 当新版特征库导致误报率显著上升或引发业务异常时，管理员可将特征库回滚至出厂默认版本或其他稳定版本，确保业务连续性。 2.1.2 MD5规则 MD5规则是基于文件数字指纹（MD5哈希值）定义的检测规则，用于快速判断传输文件是否为已知恶意样本。由于同一文件无论存储位置如何变化其MD5值保持不变，因此该方法具有极高的识别效率和一致性。 设备在本地维护一个MD5规则库，包含大量已知病毒文件的哈希值。当检测到文件时，首先计算其MD5值并与本地库比对，若匹配成功则直接判定为病毒。 此外，未命中本地库的文件还可通过云端查询或智能平台增强检测进一步分析，结果将缓存于本地MD5值缓存中，供后续相同文件快速比对使用。 2.1.3防病毒动作 防病毒动作是指对检测到病毒的报文所采取的处理策略，包括如下几种类型： •告警：允许报文通过，同时生成日志记录，适用于监控阶段或低风险场景。•阻断：直接丢弃报文，阻止病毒传播，适用于高危威胁。•重定向：仅针对HTTP上传方向，将用户访问跳转至提示页面，告知其文件存在风险。 所有动作均可生成病毒日志，并支持输出至信息中心或通过邮件发送给指定收件人，便于审计与溯源。 2.1.4防病毒例外 防病毒例外机制通过灵活配置特征、应用和文件级例外规则，在确保安全防护的同时有效减少误报、优化性能并保障业务连续性。 防病毒例外包括如下类型： •病毒特征例外：将确认为误报的病毒特征加入例外列表，避免合法流量被拦截。•应用协议例外