I had a similar (but not identical) problem running the Comodo Verification Engine (version 2, 4, 0, 6) browser plugin with Sandboxie as reported in thread http://sandboxie.com/phpbb/viewtopic.php?t=1364. I found that VE was not allowing Sandboxie to close up the sandbox when exiting the browser. The Sandboxie Control Console continued to show vengine.exe running after the browser was closed. I added the following to the Sandboxie configuration file which has solved the problem for me:

LingerProcess=vengine.exe

I tested this solution with both Internet Explorer & FireFox. I did note that Verification Engine tends to leave extra tray icons behind, even though the associated process actually closes properly in task manager. On mouse over, the unused VE icons disappear. Hope this helps others.

I had the original snag to which you referred. Comodo Verification Engine works for me now after I prevented it from starting on bootup; a handy little program.

A question for you on these helper programs - and proxomitron is another one my browser calls on: these are being called on through the wall of the sandbox. Does this represent a security vulnerability; should these helper programs be forced to run inside the sandbox when called upon?

It has been my experience that browser plug ins & add ons which are invoked by a sandboxed browser get sandboxed as well without having to be forced. I am unfamiliar with proxomitron but a quick check of Sandboxie's control panel will show whether or not it is sandboxed when the browser running. If things are working correctly for you, Comodo's Verification Engine (vengine.exe) will show up in the control panel as well. I have noticed that other plug ins (like PDF viewers) automatically get sandboxed while in use.

Check the Sandboxie control panel to see if proxomitron is automatically getting sandboxed. If it is not, hopefully someone with a greater understanding of proxy servers and associated risks will be better able to address your specific proxomitron security concerns.

Good thinking. No, though, neither the verification engine nor proxomitron are operating in the sandbox, but then it's the easiest thing to force them to and probably play safe. Interesting question though and I'm sure it must have been asked before.

Thanks

martinr, I noticed the difference between our setups is that I still allow CVE to run at startup. I altered my setup to match yours and you are right, vengine.exe no longer shows up as sandboxed, nor does it show up in task manager. And no tray icon. But it still works! I can't see any system services associated with CVE which leaves me completely puzzled as to how it functions. I am now thinking that vengine.exe just displays the tray icon.