How to determine if an exe file has been compressed using UPX

Question

Is there a way to determine if an exe file has been compressed using UPX?

The function that determines if the exe file was compressed is fine, except that I found a problem with the code. If the function IsUPXCompressed is called, you are trying to run upx, upx cannot save the file that it modifies. There is something in the function that does not correctly distribute the rights. I checked this for a few hours. If I do not call the method, then UPX can write files without problems. You call it and then try to run UPX, it will not save the file. UPX reports an IOException when trying to write a file.

Can someone detect something wrong in the code that will cause this problem?

Thanks

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The function that determines if the exe file was compressed is fine, except that I found a problem with the code. If the function IsUPXCompressed is called, you are trying to run upx, upx cannot save the file that it modifies. There is something in the function that does not correctly distribute the rights. I checked this for a few hours. If I do not call the method, then UPX can write files without problems. You call it and then try to run UPX, it will not save the file. UPX reports an IOException when trying to write a file.

Can someone detect something wrong in the code that will cause this problem?

Thanks

Answer 1

, exe UPX, PE- UPX0, UPX1 .., , UPX , exe UPX.

uses 
Windows;

function IsUPXCompressed(const Filename:TFileName): Boolean;
var
  i             : integer;
  pBaseAddress  : PByte;
  pDosHeader    : PImageDosHeader;
  pNtHeaders    : PImageNtHeaders;
  hFile         : Cardinal;
  hFileMap      : Cardinal;
  pSectionHeader: PImageSectionHeader;
  dwOffset      : Cardinal;
  SectName      : AnsiString;
begin
  Result:=False;

  hFile := CreateFile(PChar(Filename), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
  if (hFile = INVALID_HANDLE_VALUE) then Exit;

  hFileMap := CreateFileMapping(hFile, nil, PAGE_READONLY or SEC_IMAGE,  0, 0, nil);
  if (hFileMap = 0) then
  begin
    CloseHandle(hFile);
    Exit;
  end;

  pBaseAddress := MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, 0);
  if (pBaseAddress = nil) then
  begin
    CloseHandle(hFileMap);
    CloseHandle(hFile);
    Exit;
  end;

  try
      dwOffset   := Cardinal(pBaseAddress);
      pDosHeader := PImageDosHeader(pBaseAddress);
      pNtHeaders := PImageNtHeaders(dwOffset + Cardinal(pDosHeader._lfanew));
      pSectionHeader := pImageSectionHeader(Cardinal(pNtHeaders) + SizeOf(TImageNtHeaders));
      for i := 0 to pNtHeaders.FileHeader.NumberOfSections-1 do
      begin
        SetString(SectName, PAnsiChar(@pSectionHeader.Name), SizeOf(pSectionHeader.Name));
        Result:=Pos('UPX',SectName)>0;
        If Result then break;
        Inc(pSectionHeader);
      end;

  finally
    UnmapViewOfFile(pBaseAddress);
    CloseHandle(hFileMap);
    CloseHandle(hFile);
  end;

end;

Answer 2

upx?

Answer 3

UPX :

if (memcmp(isection[0].name,"UPX",3) == 0)
    throwAlreadyPackedByUPX();

32- PE; 64- PE , .

#include <stdio.h>

typedef unsigned int uint;

uint peek_d( FILE* f, uint offs ) {
  fseek( f, offs, SEEK_SET );
  uint a = 0;
  fread( &a, 1,sizeof(a), f );
  return a;
}

int main( int argc, char** argv ) {

  FILE* f = fopen( argv[1], "rb" ); if( f==0 ) return 1;

  uint p,n,x,y;

  p = peek_d( f, 0x3C ); // PE header offset
  n = peek_d( f, p+0x74 ); // pointer table size
  x = p + 0x78 + n*8;
  y = peek_d( f, x+0*0x28+0 ); // 1st section name

  if( (y&0xFFFFFF) == ('U'+('P'<<8)+('X'<<16)) ) {
    printf( "UPX detected!\n" );
  } else {
    printf( "No UPX!\n" );
  }

  return 0;
}

Answer 4

// IsUPXCompressed - Delphi 2010

function IsUPXCompressed( const Filename: TFileName ): Boolean;
var
  i: integer;
  pBaseAddress: PByte;
  pDosHeader: PImageDosHeader;
  pNtHeaders: PImageNtHeaders;
  hFile: Cardinal;
  hFileMap: Cardinal;
  pSectionHeader: PImageSectionHeader;
  dwOffset: Cardinal;
  SectName: AnsiString;
begin
  Result := False;
  hFile := CreateFile( PChar( Filename ), GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0 );
  if ( hFile = INVALID_HANDLE_VALUE ) then
    Exit;
  hFileMap := CreateFileMapping( hFile, nil, PAGE_READONLY or SEC_IMAGE, 0, 0, nil );
  if ( hFileMap = 0 ) then
  begin
    CloseHandle( hFile );
    Exit;
  end;
  pBaseAddress := MapViewOfFile( hFileMap, FILE_MAP_READ, 0, 0, 0 );
  if ( pBaseAddress = nil ) then
  begin
    CloseHandle( hFileMap );
    CloseHandle( hFile );
    Exit;
  end;
  dwOffset := Cardinal( pBaseAddress );
  pDosHeader := PImageDosHeader( pBaseAddress );
  pNtHeaders := PImageNtHeaders( dwOffset + Cardinal( pDosHeader._lfanew ) );
  pSectionHeader := pImageSectionHeader( Cardinal( pNtHeaders ) + SizeOf( TImageNtHeaders ) );
  for i := 0 to pNtHeaders.FileHeader.NumberOfSections - 1 do
  begin
    SetString( SectName, PAnsiChar( @pSectionHeader.name ), SizeOf( pSectionHeader.name ) );
    if Pos( 'UPX', SectName ) > 0 then
    begin
      Result := True;
      exit;
    end;
    Inc( pSectionHeader );
  end;
end;

.

Answer 5

UPX. mabebe , . . Ypu copmpressor UPX .