Le Delphi: Criando seu Primeiro AntiVírus, #AnonM4k3r

function IsInfected(Arquivo : TFileName;CheckSum : DWORD) : BOOLEAN;
var
hFile, hMap : THandle;
pMemory : Pointer;
header, csum, sHigh, sLow : DWORD;
NtHeader : PImageNtHeaders;
CheckSumMappedFile : function(Base***ress : Pointer;FileLength : DWORD;HeaderSum, CheckSum : PDWORD) : PImageNTHeaders;
*****
Free;
begin
pMemory := nil;
Result := False;
header := 0;
csum := 0;
hFile := CreateFile(PChar(Arquivo), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, 0, 0);
if hFile = INVALID_HANDLE_VALUE then begin
Exit;
end;
sLow := GetFileSize(hFile, Pointer(@sHigh));
hMap := CreateFileMapping(hFile, nil, PAGE_READONLY, sHigh, sLow, nil);
if hMap = 0 then begin
goto Free;
end;
pMemory := MapViewOfFile(hMap, FILE_MAP_READ, 0, 0, 0);
@CheckSumMappedFile := GetProc***ress(GetModuleHandle('ImageHlp.dll'), 'CheckSumMappedFile');
NtHeader := CheckSumMappedFile(pMemory, sLow, @Header, @Csum);
if NtHeader = nil then begin
goto Free;
end;
Free:
UnMapViewOfFile(pMemory);
CloseHandle(hMap);
CloseHandle(hFile);
if csum = CheckSum then begin
result := true;
end;
end;