@ -88,7 +88,9 @@
< meta property = "og:description" content = "软件保护方式 功能限制 时间限制 运行时长限制 使用日期限制 使用次数限制 警告窗口 分析工具 静态分析工具 IDA W32Dasm lordPE Resource Hacker 动态分析工具 OllyDbg WinDbg 对抗分析技术 反静态分析技术 花指令 自修改代码技术 多态技术 变形技术 虚拟机保护技术 反动态分析技术 检测调试状态 检测用户态调试器" >
< meta property = "og:locale" content = "zh-Hans" >
< meta property = "og:image" content = "https://res.cloudinary.com/dozyfkbg3/image/upload/v1553759246/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/%E5%9B%BE%E7%89%871.png" >
< meta property = "og:updated_t ime" content = "2019-03-28T07:54:18.434Z " >
< meta property = "og:imag e" content = "https://res.cloudinary.com/dozyfkbg3/image/upload/v1553772615/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/%E6%8D%95%E8%8E%B71.png " >
< meta property = "og:image" content = "https://res.cloudinary.com/dozyfkbg3/image/upload/v1553773066/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/%E6%8D%95%E8%8E%B72.png" >
< meta property = "og:updated_time" content = "2019-03-28T12:37:51.266Z" >
< meta name = "twitter:card" content = "summary" >
< meta name = "twitter:title" content = "逆向工程实验" >
< meta name = "twitter:description" content = "软件保护方式 功能限制 时间限制 运行时长限制 使用日期限制 使用次数限制 警告窗口 分析工具 静态分析工具 IDA W32Dasm lordPE Resource Hacker 动态分析工具 OllyDbg WinDbg 对抗分析技术 反静态分析技术 花指令 自修改代码技术 多态技术 变形技术 虚拟机保护技术 反动态分析技术 检测调试状态 检测用户态调试器" >
@ -409,7 +411,7 @@
< / span >
< span title = "字数统计" >
194 字
928 字
< / span >
@ -423,7 +425,7 @@
< / span >
< span title = "阅读时长" >
1 分钟
3 分钟
< / span >
< / div >
@ -501,6 +503,27 @@
< li > 使调试器窗口不可用< / li >
< li > 终止调试器进程< / li >
< / ul >
< h1 id = "PE文件格式基础" > < a href = "#PE文件格式基础" class = "headerlink" title = "PE文件格式基础" > < / a > PE文件格式基础< / h1 > < h1 id = "实验1: 软件破解" > < a href = "#实验1: 软件破解" class = "headerlink" title = "实验1: 软件破解" > < / a > 实验1: 软件破解< / h1 > < h2 id = "对象" > < a href = "#对象" class = "headerlink" title = "对象" > < / a > 对象< / h2 > < p > < a href = "https://res.cloudinary.com/dozyfkbg3/raw/upload/v1553761280/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/crack.exe1" target = "_blank" rel = "noopener" > crack.exe< / a > , 28.0 KB< / p >
< ul >
< li > 无保护措施:无壳、未加密、无反调试措施< / li >
< li > 用户名至少要5个字节< / li >
< li > 输入错误验证码时输出: “Bad Boy!”< / li >
< / ul >
< h2 id = "爆破" > < a href = "#爆破" class = "headerlink" title = "爆破" > < / a > 爆破< / h2 > < ol >
< li > < p > 查找显示注册结果相关代码< br > 当输入错误验证码时, 程序会输出“Bad Boy”, 因此我们将程序拖入IDA, 以流程图显示函数内部的跳转。查找“Bad Boy”字符串, 我们可以定位到显示注册结果的相关代码: < br > < img src = "https://res.cloudinary.com/dozyfkbg3/image/upload/v1553772615/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/%E6%8D%95%E8%8E%B71.png" alt > < / p >
< / li >
< li > < p > 查找注册码验证相关代码< br > 用鼠标选中程序分支点,按空格切换回汇编指令界面< br > < img src = "https://res.cloudinary.com/dozyfkbg3/image/upload/v1553773066/%E8%BD%AF%E4%BB%B6%E7%A0%B4%E8%A7%A3/%E6%8D%95%E8%8E%B72.png" alt > < / p >
< / li >
< / ol >
< p > 可以看到, 这条指令位于PE文件的.text节, 并且IDA已经自动将地址转换为运行时的内存地址VA:< figure class = "highlight plain" > < table > < tr > < td class = "gutter" > < pre > < span class = "line" > 1< / span > < br > < span class = "line" > 2< / span > < br > < span class = "line" > 3< / span > < br > < span class = "line" > 4< / span > < br > < span class = "line" > 5< / span > < br > < span class = "line" > 6< / span > < br > < / pre > < / td > < td class = "code" > < pre > < span class = "line" > 3. 修改程序跳转< / span > < br > < span class = "line" > 现在关闭IDA, 换用OllyDbg进行动态调试来看看程序时如何分支跳转的< / span > < br > < span class = "line" > ```Ctrl+G``` 直接跳到由IDA得到的VA:```004010F9```处查看那条引起程序分支的关键指令< / span > < br > < span class = "line" > 选中这条指令, 按F2设置断点, 再按F9运行程序, 这时候控制权会回到程序, OllyDbg暂时挂起。到程序提示输入名字和序列号, 随意输入( 名字大于五个字节) , 点击ok后, OllyDbg会重新中断程序, 收回控制权, 如图: < / span > < br > < span class = "line" > < / span > < br > < span class = "line" > 验证函数的返回值存于EAX寄存器中, if语句通过以下两条指令执行< / span > < br > < / pre > < / td > < / tr > < / table > < / figure > < / p >
< p > cmp eax,ecx< br > jnz xxxxxxx< br > < figure class = "highlight plain" > < table > < tr > < td class = "gutter" > < pre > < span class = "line" > 1< / span > < br > < span class = "line" > 2< / span > < br > < span class = "line" > 3< / span > < br > < span class = "line" > 4< / span > < br > < span class = "line" > 5< / span > < br > < span class = "line" > 6< / span > < br > < span class = "line" > 7< / span > < br > < span class = "line" > 8< / span > < br > < span class = "line" > 9< / span > < br > < span class = "line" > 10< / span > < br > < / pre > < / td > < td class = "code" > < pre > < span class = "line" > 也就是说, 当序列号输入错误时, EAX中的值为0, 跳转将被执行。< / span > < br > < span class = "line" > 如果我们把jnz这条指令修改为jz, 那么整个程序的逻辑就会反过来。< / span > < br > < span class = "line" > 双击jnz这条指令, 将其改为jz, 单击" 汇编" 将其写入内存< / span > < br > < span class = "line" > < / span > < br > < span class = "line" > 可以看到此时程序执行了相反的路径< / span > < br > < span class = "line" > < / span > < br > < span class = "line" > 上面只是在内存中修改程序, 我们还需要在二进制文件中也修改相应的字节, 这里考察VA与文件地址之间的关系< / span > < br > < span class = "line" > 用LordPE打开.exe文件, 查看PE文件的节信息< / span > < br > < span class = "line" > < / span > < br > < span class = "line" > VA:```004010F9< / span > < br > < / pre > < / td > < / tr > < / table > < / figure > < / p >
< p > 根据VA与文件地址的换算公式: < br > < figure class = "highlight plain" > < table > < tr > < td class = "gutter" > < pre > < span class = "line" > 1< / span > < br > < span class = "line" > 2< / span > < br > < span class = "line" > 3< / span > < br > < / pre > < / td > < td class = "code" > < pre > < span class = "line" > 文件偏移地址 = VA - Image Base - 节偏移< / span > < br > < span class = "line" > = 0x004010F9 - 0x00400000 - 0< / span > < br > < span class = "line" > = 0x10F9< / span > < br > < / pre > < / td > < / tr > < / table > < / figure > < / p >
< p > 也就是说, 这条指令在PE文件中位于10F9字节处, 使用010Editer打开crack.exe, 将这一字节的75(JNZ)改为74(JZ),保存后重新执行,破解成功!< / p >
< h2 id = "编写注册机" > < a href = "#编写注册机" class = "headerlink" title = "编写注册机" > < / a > 编写注册机< / h2 > < ol >
< li > 查找显示注册结果相关代码< / li >
< li > 查找注册码验证相关代码< / li >
< li > 根据注册码验证代码编写注册机< / li >
< / ol >
< / div >
@ -737,7 +760,7 @@
< div class = "post-toc-content" > < ol class = "nav" > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#软件保护方式" > < span class = "nav-number" > 1.< / span > < span class = "nav-text" > 软件保护方式< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#分析工具" > < span class = "nav-number" > 2.< / span > < span class = "nav-text" > 分析工具< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#对抗分析技术" > < span class = "nav-number" > 3.< / span > < span class = "nav-text" > 对抗分析技术< / span > < / a > < / li > < / ol > < / div >
< div class = "post-toc-content" > < ol class = "nav" > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#软件保护方式" > < span class = "nav-number" > 1.< / span > < span class = "nav-text" > 软件保护方式< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#分析工具" > < span class = "nav-number" > 2.< / span > < span class = "nav-text" > 分析工具< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#对抗分析技术" > < span class = "nav-number" > 3.< / span > < span class = "nav-text" > 对抗分析技术< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#PE文件格式基础" > < span class = "nav-number" > 4.< / span > < span class = "nav-text" > PE文件格式基础< / span > < / a > < / li > < li class = "nav-item nav-level-1" > < a class = "nav-link" href = "#实验1: 软件破解" > < span class = "nav-number" > 5.< / span > < span class = "nav-text" > 实验1: 软件破解< / span > < / a > < ol class = "nav-child" > < li class = "nav-item nav-level-2" > < a class = "nav-link" href = "#对象" > < span class = "nav-number" > 5.1.< / span > < span class = "nav-text" > 对象< / span > < / a > < / li > < li class = "nav-item nav-level-2" > < a class = "nav-link" href = "#爆破" > < span class = "nav-number" > 5.2.< / span > < span class = "nav-text" > 爆破< / span > < / a > < / li > < li class = "nav-item nav-level-2" > < a class = "nav-link" href = "#编写注册机" > < span class = "nav-number" > 5.3.< / span > < span class = "nav-text" > 编写注册机< / span > < / a > < / li > < / ol > < / li > < / ol > < / div >
< / div >
@ -769,7 +792,7 @@
< i class = "fa fa-area-chart" > < / i >
< / span >
< span title = "Site words total count" > 14.9 k< / span >
< span title = "Site words total count" > 15.6 k< / span >
< / div >