Last Updated: 2006-06-16 17:16:11 UTC
by Chris Carboni (Version: 1)
In the meantime, we continue to recommend the same defenses we recommended with the Word 0-day from last month located at http://isc.sans.org/diary.php?storyid=1347. These very general best practices should help alleviate the danger until Microsoft releases a patch or more specific workarounds.
Update - We've recieved reports (Thanks Juha-Matti) that Symantec is detecting this attack.
Trojan.Mdropper.J is the detection for the malicious .xls which uses the 0-day exploit to drop Downloader.Booli.A.
The Symantec website also reports ..
Downloader.Booli.A may arrive on the compromised computer, dropped by Trojan.Mdropper.J, with the following name:
Note: %System% is a variable that refers to the System folder. By default this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
When Downloader.Booli.A is executed, it performs the following actions:
- Attempts to run Internet Explorer and inject its code into Internet Explorer to potentially bypass firewalls.
- Attempts to download a file from the following location:
Note: At the time of writing the remote file was not available.
- Saves the file as the following and if the download was successful, executes the file:
- Creates an empty file before exiting:
We'll pass on more information as we receive it.