Excel sheet not opened and embeededfile got format 255

Aspose.Cells Product Family
1

ATTENTION the file attached is malicious !!

pass : infectedd

When trying to extract embedded content in the file :

  • Can t open / unprotect the the sheet 1 and 2
  • the first sheet extract one embedded file with format type 255(UNKNOWN) ( Aspose::Cells::FileFormatType enum)
    how to get the right format to work on it ?

thanks
17893656776.zip (264.8 KB)

2

@tb9528,

Thanks for zipped archive.

We will evaluate your issue using your resource file(s) and get back to you with details.

3

@tb9528
We detected and saved the sample file through the following example code, and found that the content of the file was only an incorrect description. Please refer to the attachment. out_net.zip (247.0 KB)

The sample code as follows:

FileFormatInfo info = FileFormatUtil.DetectFileFormat(filePath + "0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad");
Console.WriteLine(info.FileFormatType);

Workbook wb = new Workbook(filePath + "0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad");
wb.Save(filePath + "out_net.xlsx");

The output:

Excel97To2003

Would you like to provide the original sample files and test code? We will check it soon.

4

Hi John.He

the UNKNOW format is from the embedded file i extracted from the “parent file” 0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad

when extracting OLE object from the sheet1 and 2 I got the two following files :

the first is format type unknown
and the second is format type xlsx

here attached the files - THEY ARE MALICIOUS !
password : infectedd
infected_ole.zip (100.6 KB)

5

@tb9528
Thank you for your feedback. By testing with the following sample code, we can reproduce the issue. Found a file whose format type cannot be detected. Regarding the current format types supported by Cells for detection, please refer to the following document.

FileFormatInfo info = FileFormatUtil.DetectFileFormat(filePath + "Embedded_0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad_null6");
Console.WriteLine(info.FileFormatType);

info = FileFormatUtil.DetectFileFormat(filePath + "Embedded_0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad_null255");
Console.WriteLine(info.FileFormatType);

The output:

Xlsx
Unknown

Also, what format type is this undetectable file?

6

Hi John.He,

Embedded_0eb9bd85b8ce62ea6d923814284a614e95c6ffc9ae7de92ee3393f9d07c0ccad_null255 is an OLE Object
(see [here ]

for specs), generally it is a way to embed and link objects within other containers (in this case an excel sheet)

the type of OLE Object is defined by the CLSID in this case

image.png (73.6 KB)

this refers to[ url moniker|CLSID 79eac9e0-baf9-11ce-8c82-00aa004ba90b | URL Moniker | STRONTIC]

which right afterwards we can see pointing to the wanted URL - which is refered to when activating the ole object by double clicking it

Is there a way to open it with Aspose tool ? if yes - can you explain how ?

I remind you that the file is MALICIOUS !! pay attention when opening it.

7

@tb9528,

Thanks for providing further details.

We need to evaluate support for detecting OLE (Object Linking and Embedding) format in details. We have opened the following new ticket(s) in our internal issue tracking system and will deliver their fixes according to the terms mentioned in Free Support Policies.

Issue ID(s): CELLSNET-56451

You can obtain Paid Support Services if you need support on a priority basis, along with the direct access to our Paid Support management team.

8

@tb9528
We are pleased to inform you that your issue has been resolved. The fix will be included in our upcoming release (Aspose.Cells for .NET 24.9) that we plan to release in the first half of September 2024. You will be notified when the next version is released.

9

Hi

Thank you for your fast response
We need this fix for we need it for Aspose.Cells for JAVA please

This will be released together ?

Thanks

10

@tb9528
Thank you for your feedback. The fix will be included in our upcoming release (Aspose.Cells for Java 24.9) that we plan to release in the first half of September 2024. You will be notified when the next version is released.

11

@tb9528,

The upcoming Aspose.Cells for Java v24.9 will support to detect OLE (Object Linking and Embedding) format and FileFormatType.OLE will be returned.

Yes, generally, both .NET and Java releases are published on the same day or on alternative days.

12

Thank you both,

I am waiting for the update :slight_smile:

13

@tb9528,

Sure, we will keep you posted with updates/fixes (once available).