Another Method, when a exe is packed with the UPX tool, the section of the PE header contains sections called UPX0
,UPX1
, etc. so if read these sections and compare the name with the string UPX
you can determine if the exe was compressed using the UPX packer.
check this function
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;