ZipCreate produces virus

Sorry if I sound alarmist.

I have an application being used in a large geographical area. On a regular basis, the users take backups of the data and send them to a central office. The database is MySQL so I use MySQLDump to extract the data into a text file and then compress it (with password) using the ZipCreate function. This compressed data is either emailed or hand delivered.

Yahoo mail is rejecting the attached data claiming it has detected a virus in the data. Is there any way to resolve this? Please help me out.

Thanks

issah

Hi Issah...

Many email system reject all zip files on general principles... (gmail does the same)...

Genrally changing the extension of the file is enough to solve the problem... Personnaly, I rename my zip files in zap and they pass through without any problem

Best regards

Fabrice Harari
Windev, WebDev, WinDev Mobile consulting

Thanks for the reply.

The problem seems to be that I am zipping with password as such the files are encrypted. If I remove the password, all goes through but then the security of the data is compromised.

Name and file extension changes are not working. This is specifically for yahoo mail.

Any more suggestions?

issah

Hi Again...

So we are in a situation where encrypting with the password generate a string recognized as a virus... The solution would be to change the file content before sending it...

So you can use fcrypt to encrypt the file after zipping it (you can choose different encryption methods so you should find one not creating the problem)...

And of course, in that case, it's not necessary to use a password on the zip file anymore (but you still can of course)

Best regards

Fabrice Harari
WinDev, WebDev, WinDev Mobile Video Courses



Edited 1 time(s). Last edit at 10/21/2008 11:31PM by Fabrice Harari.

Hello Issah

Interesting issue and one that is typical of the way things seem to work these days.

This rejection of the file is not because of anything you are doing wrong, the problem is with Yahoo mail and your client.

You have fulfilled your obligation in provided a zipped and encrypted file and it is now your client's responsibility to engage a delivery mechanism to transmit that file.

Why are they persisting in using Yahoo mail when it refuses the file ?

I do appreciate that you need to be diplomatic in your dealing with your client but it seems that your hands are tied if they insist on using Yahoo mail and I would tell them so.

In terms of a solution, will your client set up a central ftp site so that they can just send the files to it without using email ?

Regards
Al




Edited 1 time(s). Last edit at 10/21/2008 11:37PM by Al.

Thanks Fabrice and Al for your contributions. I have been playing around with file names and formats and even password changes. For now, the zip format doesn't work as long as its is password protected, though I am yet to test if this is the case if the zipping is done using a tool like winzip etc. The .cab format does not support passwords and as such not secure and the .wdz format works but is double the size.

I have been considering using fcrypt and fcompress/zip but this will be a last alternative as I wanted a format that I could open outside of the application with winzip or winrar using the password in the event that I have to do some manual tinkering etc.

Changing from yahoo mail, at least 70 people nation-wide would be pissed. I have been looking for a way of contacting either yahoo or symantec for them to validate the format and fine-tune their virus engine but no cigar.

Thanks and will keep you posted if I find anything.

issah

Just an update for those interested in the yahoo mail zip reject issue. Took a text file and zipped it with winrar (password protected), which was subsequently rejected by yahoo mail. The good news is that its not limited to windev's implementation of the zip library.

issah

Hello Issa

Try to zip twice the file.
The second zip operation without a pass...

Hi Mohammed,

such issues are a frequently experienced problem on the web. Worst of all are the disapearing .exe files - deleted in our own interest. So they say.

My solution: rename the file and everything's working fine. All exe-files (in fact updates) are sent as ese-files and have to be renamed by the recipient of the update to exe. Virus scanners ignore .ese because they don't know their purpose.

So, if a zip-file is not received, why not rename it to .jpg? jpeg-files can be of any content and only the weakest of the virus scanners look into a jpg-file. Of course, the mail has to include the instruction how to store, rename and apply an update.

Kind regards,
Guenter