For the paranoid: deleting Flash local storage objects

Thursday, October 30. 2008

For the paranoid: deleting Flash local storage objects

I'm reasonably careful about the cookies I accept from Web sites - I don't want companies to be able to track every site I visit, for example, so that they can build a nice little profile about me. It's for the protection of the companies more than anything else: someone there might die of extreme boredom following the trail of "Evergreen", "Linux Weekly News", "Python docs"...

However, I recently learned about Flash "local storage objects" (LSO), which are similar to browser cookies but capable of storing much richer information and also completely inscrutable in terms of the effectiveness of Adobe's security model. Is Flash really capable of preventing a Flash application running on microsoft.com from accessing an LSO from mail.google.com? I certainly don't know, and as Flash is a closed-source application it's hard for anyone except for the developers at Adobe to know--but I bet there are people extremely motivated to find out. (Insert obligatory "See? Closed source sucks!" comment here.)

So, in my crude attempt to prevent too much garbage accumulating due to the occasional YouTube video or NBC Saturday Night Live skit that I might watch, I've added the following rules to my cron entries to delete my entire set of LSOs every four hours:

5 ∗/4 ∗ ∗ ∗ rm -fr /home/dan/.macromedia/Flash_Player/#SharedObjects 
5 ∗/4 ∗ ∗ ∗ rm -fr /home/dan/.macromedia/Flash_Player/macromedia.com/support/flashplayer/sys/

You Windows users can probably do something similar, but I haven't bothered to track that down yet. Sorry.

Posted by Dan Scott in Personal at 07:24 | Comments (8)

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Macromedia's Documentation:
http://www.macromedia.com/support/documentation/en/flashplayer/help/help02.html

Launch the Flash Global settings:
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager03.html#117498

It doesn't say where the files are stored though...

#1 Mike Z on 2008-10-31 13:25 (Reply)

C:\Documents and Settings\{user}\Application Data\Macromedia\Flash Player#SharedObjects

#1.1 Anonymous on 2009-02-14 00:08 (Reply)

Thanks! I'm sure that will help someone!

#1.1.1 Dan Scott (Homepage) on 2009-02-15 11:26 (Reply)

For Microsoft Windows systems, instead of using the Linux/Unix "rm" command, use the DOS "deltree" command. For example:

deltree /Y "C:\Documents and Settings\{user}\Application Data\Macromedia\Flash Player#SharedObjects\*"
deltree /Y "C:\Documents and Settings\{user}\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\*"

The /Y parameter forces the command to execute unconditionally without prompting for every file in the subfolder.

The two commands can be put into a MS-DOS batch file that is executed from autoexec.bat every time the system boots, or create a shortcut to the batch file that runs in a minimized window and call the shortcut from the Task Scheduler at the intervals that you desire. You can also make the shortcut available on your desktop or in the Programs menu, whatever is convenient, to run manually. (I tested this on an old Windows 98SE system. Details may vary with later versions of Windows.)

#1.1.2 Phil Cooper on 2010-05-25 13:01 (Reply)

Many thanks for these updates, Phil! I'm sure others will thank you, too.

#1.1.2.1 Dan Scott on 2010-05-25 20:27 (Reply)

In my Ubuntu Linux 8.10 installation the path after Flash Player#SharedObjects adds another level, which appears to be an installation-specific randomly generated directory name, e.g., /TE26HJV9, and all the LSOs are a level below that. I found that it's OK to blow it away, as Flash will create a new randomly named directory the next time it runs. The script won't work a second time if that directory is included in the path of the first line, since it changes the next time Flash runs.

#2 Phil Cooper on 2010-05-25 11:35 (Reply)

On Mac, it's

~/Library/Preferences/Macromedia/Flash Player/#SharedObjects

#3 Steve on 2010-06-03 16:52 (Reply)

Great. Can someone also tell me where Silverlight cookies are stored? In Windows? in linux for Moonlight? and Mac? Can they be deleted as easily as Flash cookies?

#4 Neuromancer on 2010-06-23 21:25 (Reply)

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About Me

I'm Dan Scott: barista, library geek, and free-as-in-freedom software developer. I hack on projects such as the Evergreen open-source ILS project and PEAR's File_MARC package .

By day I'm the Systems Librarian for Laurentian University. You can reach me by email at dan@coffeecode.net.

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