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insensitive, that is, the meaning of Function rightpos (const substr, S: string): integer;VaRIPOs: integer;Tmpstr: string;BeginTmpstr: = s;IPOs: = pos (substr, tmpstr); Result: = 0;// Find the location where substr appears for the first timeWhile IPOs BeginDelete (tmpstr, 1, IPOs + Length (substr)-1 );// Delete the searched charactersResult: = Result + IPOs;IPOs: = pos (substr, tmpstr); // find the position where the substr appearsIf IPOs = 0 Then break;Result: = Result + Length (substr)-1;End

1) classic comparison, usually at the registration code (by programhunter)1MoV eax [] can be an address or another register.MoV edX [] the preceding two addresses usually store important information.Call 00 ??????Test eaxJZ (jnz)2MoV eax [] can be an address or another register.MoV edX [] the preceding two addresses usually store important information.Call 00 ??????JNE (JE)3MoV eax []MoV

, ADDR buffer1, 128 Invoke wsprintf, ADDR buffer, ADDR template, wparam Invoke lstrcmpi, ADDR buffer, ADDR buffer1 . If eax! = 0 Invoke setdlgitemtext, hdlg, idc_handle, ADDR Buffer . Endif Invoke getdlgitemtext, hdlg, idc_classname, ADDR buffer1, 128 Invoke getclassname, wparam, ADDR buffer, 128 Invoke lstrcmpi, ADDR buffer, ADDR buffer1 . If eax! = 0 Invoke setdlgitemtext, hdlg, idc_classname, ADDR Buffer . Endif Invoke getdlgitemtext, hdlg, idc_wndproc, ADDR buffer1, 128 Invoke getclasslong,

computer tests, only through their own test, the magic is not much difference in Ubuntu, the problem is said later), and then I compile, look at their assembly code, found a mysterious thing I do not understand. The following are the assembly codes for the If-else and three mesh operations respectively. 37:if (a>b) 00401079 mov ecx,dword ptr [ebp-10h] 0040107C cmp ecx,dword ptr [ebp-14h] 0040107F jle main+79h (00401089) 38:temp=a; 00401081 mov edx,dw

Several novice programmers won the Kaggle Predictive modeling contest after enrolling for a few days of "machine learning" courses on Coursera for free. The big data talent scare that the industry has made in it--McKinsey is the initiator--has raised expectations and demands for big data and advanced analytics talent, and data scientists have become the sexiest career of the night, with its halo chasing sports stars. Data scientists are portrayed as G

Different compilers may produce different codes, resulting in different results. The Code is as follows: #include Environment: win7 Compiler: GCC IDE: vc ++ 6.0/DEV-C ++ Result: q = 22 : Q = (++ j) + (++ mov eax, dword ptr [ebp-] Move J = add eax, add 1 to the Register eax value, eax = 0040103C mov dword ptr [ebp-], eax moves the register value to the variable j, j = 0040103F mov ecx, dword ptr [ebp-] Move J = add ecx, in the register, ecx +, j = mov dword ptr [ebp-], ecx moves the value on

| pDebugEvent = 0012ED7C0012DC94 000003E8 Timeout = 1000. MS0012DC98 7C930738 ntdll.7C930738 Locate CD90 in the data window and check the OEP value. Now go to the code window Ctrl + G: 0181c386Ctrl + f search command at the current location: or eax, 0FFFFFFF8Locate the first place in 0181c956, on which cmp dword ptr ss: [ebp-A34], where 0 sets the breakpoint. 0181C90A> 83BD CCF5FFFF> cmp dword ptr ss: [EBP-A34], 0 // off, Shift + F9 interrupt down to [ebp-A34] = [0012CD7C] = 000001B7 clear 0018

After the system patch is completed, the online blind irrigation is still connected to www.net.cn. now .... put down his network horse, 8 error, really good. kill 98. nt.2000.xp. xpsp2.2003. I kept it myself and analyzed his Trojan. A traffic Trojan. Server. Now all the ponies are here.Slightly shelled, written in VB.00403DAD. FF15 54104000 call dword ptr ds: [00403DB3. 8985 E0FCFFFF mov dword ptr ss: [EBP-320], EAX00403DB9. EB 0A jmp short Rundll32.00403DC500403DBB> C785 E0FCFFFF> mov dword ptr

will break down the BPX shell_policyicona breakpoint and use F12 to check if the software is called and the parameters are used! First come to the following: Here is where the software is called at startup: * Possible reference to string resource id = 00114: "CCProxy"|: 00408770 6a72 push 00000072: 00408772 51 push ECx: 00408773 c681_f0000000005 mov byte PTR [esp + 000024f4], 05: 0040877b e8c0890100 call 00421140: 00408780 83c408 add ESP, 00000008: 00408783 50 push eax: 00408784 8d4c2414 Lea EC

][-----------------------------------------------------------]The example of shellcode below can effectively deal with NaI Entercept. The method used is to rewrite the function header.[-----------------------------------------------------------] // This sample code overwrites the preamble of winexec and// Createprocessa to avoid detection. The Code then// Callwinexec with a "calc.exe" parameter.// The Code demonstrates that by overwriting Function// Preambles, it is able to evade Entercept and

Mul: Unsigned Multiplication ; Influence of, CF flag bit; Command Format:; Mul R/m; parameter is the multiplier; if the parameter is R8/M8, the Al will be used as the multiplier and the result will be placed in ax; if the parameter is R16/M16, ax will be used as the multiplier and the result will be placed in eax; if the parameter is R32/M32, eax will be used as the multiplier and the result will be placed in edX: eax ; Test27_1.asm.38

, 0x4; _ cdeclTest eax, eax; if the returned value is nullJnz short msvcr120116fb0c2a1Lea ECx, dword ptr ss: [EBP-0x10]Call bad_alloc; call bad_allocPush msvcr120108fb753d8Lea edX, dword ptr ss: [EBP-0x10]Push edXCall _ cxxthrowexception; call _ cxxthrowexceptionJMP short msvcr120116fb0c266MoV eax, dword ptr ss: [EBP-0x4]; not equal to null, return value to eax, return to Main FunctionMoV ESP, EBPPop EBPRetn Because vs2013 cannot view its implementati

great superiority of the C ++ language in object-oriented design. Let's take a look at how this virtual works? 76: employee p;0040128D lea ecx,[ebp-10h]00401290 call @ILT+45(employee::employee) (00401032)00401295 mov dword ptr [ebp-4],077: manager m;0040129C lea ecx,[ebp-14h]0040129F call @ILT+65(manager::manager) (00401046)004012A4 mov byte ptr [ebp-4],178: employee* e = p;004012A8 lea eax,[ebp-10h]004012AB

is modified, Kabbah does not report any virus when it is added to other executable files in this way. The modified program ensures the re-running of the program, otherwise, this modification is meaningless. Start the operation. The following eight most common shells are prepared. I. First test nspack3.6 Load the DT with the nspack shell with OD, and copy the top 10 lines as follows (the blue bold area is the part to be modified, as shown in the following format)004cf302 E8 00000000 call duplica

54975700 push game.00579754; ASCII ". \ datapool \ gmdp_characterdata.cpp" 0044b2a7 68 48975700 push game.00579748; ASCII "ct_monster" 0044b2ac 68 20975700 push game.00579720; ASCII "character must not % s, (File: % s line: % d )" 0044b2b1 ffd7 call EDI 0044b2b3 83c4 10 Add ESP, 10 0044b2b6 8b4e 04 mov ECx, dword ptr ds: [ESI + 4] 0044b2b9 8b11 mov edX, dword ptr ds: [ECx] 0044b2bb ff92 14010000 call dword ptr ds: [

{2002.8.5 kingron} {Source: Source string} {Sub: Sub string} {Return: Count} {Ex: strsubcount ('abccdcd', 'bc') = 2} Function strsubcount (const source, Sub: string): integer; VaR Buf: string; I: integer; Len: integer; Begin Result: = 0; Buf: = source; I: = pos (sub, Buf ); Len: = length (sub ); While I Begin INC (result ); Delete (BUF, 1, I + len-1 ); I: = pos (sub, Buf ); End; End; {strsubcount} {The following function returns the position after the specified position of substr in S}{Example:

known to be tuned in the control function and its argument list (stored in aIn the Tvarrec array), how to pass the arguments in when it is called. This requires a few preliminary knowledge:1. First let's take a look at this parameter list: Params. Its type is called variable-open by Delphi.Array of Tvarrec (Variant Open array), which means that the Params is aA member is an array of Tvarrec. In other words, when parameters are passed into the Params, various types areDelphi Automatic conversion

table are in the exception_table_entry structure: struct exception_table_entry{ unsigned long insn, fixup;}; Insn is the linear address of the instruction to access the process address space. When a page-missing exception is triggered by commands in the insn unit, fixup is the assembly instruction code address to be called. Generally, this assembly code forces the service routine to return an error code to the user-state process. Insert a table item to the exception table through the Assembl

Topic: 3.63 Score: Two-point job process:int sum_col (int n,int a[e1 (n)][e2 (n)],int j) { int i; int result = 0; for (I=0;iAbove is the original codeAssembly codeMOVL 8 (%EBP),%edx; edx:n Leal (%edx,%edx),%eax; eax:2n leal-1 (%eax),%ecx ; ecx:2n-1 Leal (%eax,%edx),%esi; esi:3n, (E1 (n)) Movl $0,%eax; E ax:0 (

from left to right. We are still confident that the suffix-specific method and multiplication have a higher operation priority, so we will soon prove ourselves that there is no order in which we can calculate I ++, add up and multiply the three array elements to get 60. Now I am fascinated by this. My first thought was to check the disassembly code of the code and try to find out what actually happened. I used the debug symbol debugging symbols) to compile this sample code. After using objdump,