在浅谈VB6逆向工程(3)中
代码：
Dim a //注意：这里定义的是变体变量。
//如果不用变体变量，编译器将优化掉太多的代码。:(
//当你熟悉变体类型后，其他的将很容易分析 ^_^
a = 5
If a < 5 Then
MsgBox ("a < 5")
ElseIf a = 5 Then
MsgBox ("a = 5")
Else
MsgBox ("a > 5")
End If
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
反汇编代码：
00401A72 XOR ESI,ESI
00401A74 MOV EDI,5
00401A79 MOV DWORD PTR SS:[EBP-74],ESI
00401A7C LEA EDX,DWORD PTR SS:[EBP-74]
00401A7F LEA ECX,DWORD PTR SS:[EBP-24]
00401A82 MOV DWORD PTR SS:[EBP-24],ESI
00401A85 MOV DWORD PTR SS:[EBP-34],ESI ----> 这些变量是为 MsgBox 使用的
00401A88 MOV DWORD PTR SS:[EBP-44],ESI |
00401A8B MOV DWORD PTR SS:[EBP-54],ESI |
00401A8E MOV DWORD PTR SS:[EBP-64],ESI ---
00401A91 MOV DWORD PTR SS:[EBP-6C],EDI // 5
00401A94 MOV DWORD PTR SS:[EBP-74],2 //整数类型
00401A9B CALL DWORD PTR DS:[<&MSVBVM60.__vbaVarMove>]//赋值
//到这里 a = 5 //[ebp-24]
00401AA1 LEA EAX,DWORD PTR SS:[EBP-24]
00401AA4 LEA ECX,DWORD PTR SS:[EBP-74]
00401AA7 MOV EBX,
8002
00401AAC PUSH EAX
00401AAD PUSH ECX
00401AAE MOV DWORD PTR SS:[EBP-6C],EDI // 5
00401AB1 MOV DWORD PTR SS:[EBP-74],EBX // 8002
00401AB4 CALL DWORD PTR DS:[<&MSVBVM60.__vbaVarTstLt>] // a < 5 ?
00401ABA TEST AX,AX
00401ABD JE SHORT 工程2.00401AE4 //不小于则跳走
00401ABF MOV ECX,80020004
00401AC4 MOV EAX,0A
00401AC9 MOV DWORD PTR SS:[EBP-5C],ECX
00401ACC MOV DWORD PTR SS:[EBP-64],EAX
00401ACF MOV DWORD PTR SS:[EBP-4C],ECX
00401AD2 MOV DWORD PTR SS:[EBP-54],EAX
00401AD5 MOV DWORD PTR SS:[EBP-3C],ECX
00401AD8 MOV DWORD PTR SS:[EBP-44],EAX
00401ADB MOV DWORD PTR SS:[EBP-6C],工程2.004016C4; UNICODE "a < 5"
00401AE2 JMP SHORT 工程2.00401B63
00401AE4 LEA ECX,DWORD PTR SS:[EBP-24]
00401AE7 LEA EDX,DWORD PTR SS:[EBP-74]
00401AEA PUSH ECX
00401AEB PUSH EDX
00401AEC MOV DWORD PTR SS:[EBP-6C],EDI // 5
00401AEF MOV DWORD PTR SS:[EBP-74],EBX // 8002
00401AF2 CALL DWORD PTR DS:[<&MSVBVM60.__vbaVarTstEq>]// a = 5 ?
00401AF8 TEST AX,AX
00401AFB MOV ECX,80020004
00401B00 MOV EAX,0A
00401B05 MOV DWORD PTR SS:[EBP-5C],ECX
00401B08 MOV DWORD PTR SS:[EBP-64],EAX
00401B0B MOV DWORD PTR SS:[EBP-4C],ECX
00401B0E MOV DWORD PTR SS:[EBP-54],EAX
00401B11 MOV DWORD PTR SS:[EBP-3C],ECX
00401B14 MOV DWORD PTR SS:[EBP-44],EAX
00401B17 JE SHORT 工程2.00401B5C //不相等则跳走
[招生]科锐逆向工程师培训(2025年3月11日实地，远程教学同时开班, 第52期)！
