Colasoft Blog

We provide some tips on monitorring FBHOLE worm. In this article, we specificlly provide a step by step guide on how to build a fileter and monitor FBHOLE worm with Capsa network analyzer.

1. On the Start Page, click Packet Filter Settings link to open the Filter dialog box, which organizes all the filters.

2. Click the Add button (on the bottom-left corner of the dialog box) to build a new filter.

3.In the new window, choose Advanced Filter tab. And click the And icon. Choose Content from the context menu.

4. In the Pattern Rule window, just enter keyword: fbhole.com in the Pattern text box. Then click OK to close the window.

5. Click OK again to close the Packet Filter window.

6. Check the Accept checkbox of the filter just built which enables the program only capture the packets containing keyword “fbhole.com”.

7. Click OK and then start a capture.

8. If there is already a project running, you’d better stop it to build the filter and restart the capture. To build a filter in a running project: click the Filter button on the Ribbon. You will also see the Filter dialog box as well.

Facebook users have to be very careful when they’re hanging out on Facebook because a new worm called FBHOLE is out there everywhere. According to the reports that FBHOLE “doesn’t seem to be doing anything else than posting a message to people’s Facebook walls”. As an innovative network security software provider, Colasoft responses to analyze the worm immediately and we do get some ideas to help keep our users away from FBHOLE worm.

Behavior Study

If you click any post link like: http://www.fbhole.com/omg/allow.php?s=a&r=[random number] (post name” try not to laugh xD”) on a post wall, you will probably be lead to a page like the figure below:

Figure 1: try not to laugh xD with a fbhole.com link

The web page pops up a message box tells that there are some errors. Of course you will click the OK button to close the dialog box readily. Once you click the OK button, you may find there is one more post submitted to your wall.

Figure 2: Error messages

After the study of the HTML and scripts of the web page, we find that wherever you click on this page, you will trigger a script that tries to submit the same post to your Facebook wall. All these are done by a hidden iframe showing below:

Figure 3: iFrame code

This iframe follows your mouse movements. Wherever you click on the page, you will always click the invisible “Publish” button.

Tips to keep your network away from FBHOLE worm:

Until now we find that is all it does without any further harm to your computer system. To help keep our users to away fromthis worm, we do have some suggestions:

1. Inform the users in your network not click any links shown in the Figure 1.
2. Set up a filter to monitor which users click these links.
3. Locate the computer and scan it with an anti-virus program because there are possibilities that the worm may evolve to infect the operation system.