Last week when I was testing the latest version of RootkitRevealer (RKR) I ran a scan on one of my systems and was shocked to see evidence of a rootkit. Rootkits are cloaking technologies that hide files, Registry keys, and other system objects from diagnostic and security software, and they are usually employed by malware attempting to keep their implementation hidden (see my “Unearthing Rootkits” article from thre June issue of Windows IT Pro Magazine for more information on rootkits).
...
I doubted that the files had any version information, but ran my Sigcheck utility on them anyway. To my surprise, the majority did have identifying product, file and company strings. I had already recognized Dbghelp.dll and Unicows.dll as Microsoft Windows DLLs by their names. The other files claimed to be part of the “Essential System Tools” product from a company called “First 4 Internet”
...
I Googled the company name and came across this article, confirming the fact that they have deals with several record companies, including Sony, to implement Digital Rights Management (DRM) software for CDs.
The DRM reference made me recall having purchased a CD recently that can only be played using the media player that ships on the CD itself and that limits you to at most 3 copies. I scrounged through my CD’s and found it, Sony BMG’s Get Right with the Man (the name is ironic under the circumstances) CD by the Van Zant brothers.
...
At that point I knew conclusively that the rootkit and its associated files were related to the First 4 Internet DRM software Sony ships on its CDs. Not happy having underhanded and sloppily written software on my system I looked for a way to uninstall it. However, I didn’t find any reference to it in the Control Panel’s Add or Remove Programs list, nor did I find any uninstall utility or directions on the CD or on First 4 Internet’s site. I checked the EULA and saw no mention of the fact that I was agreeing to have software put on my system that I couldn't uninstall. Now I was mad.
I deleted the driver files and their Registry keys, stopped the $sys$DRMServer service and deleted its image, and rebooted. As I was deleting the driver Registry keys under HKLM\System\CurrentControlSet\Services I noted that they were either configured as boot-start drivers or members of groups listed by name in the HKLM\System\CurrentControlSet\SafeBoot subkeys, which means that they load even in Safe Mode, making system recovery extremely difficult if any of them have a bug that prevents the system from booting.
When I logged in again I discovered that the CD drive was missing from Explorer. Deleting the drivers had disabled the CD. Now I was really mad.
...
I opened Device Manager, displayed the properties for my CD-ROM device, and saw one of the cloaked drivers, Crater.sys (another ironic name, since it had ‘cratered’ my CD)
...
Filter registrations are stored in the Registry under HKLM\System\CurrentControlSet\Enum so I opened Regedit and searched for $sys$ in that key. I found the entry configuring the CD’s lower filter.
I deleted the entry, but got an access-denied error. Those keys have security permissions that only allow the Local System account to modify them, so I relaunched Regedit in the Local System account using PsExec: psexec –s –i –d regedit.exe. I retried the delete, succeeded, and searched for $sys$ again. Next I found an entry configuring another one of the drivers, Cor.sys (internally named Corvus), as an upper filter for the IDE channel device and also deleted it. I rebooted and my CD was back.
The entire experience was frustrating and irritating. Not only had Sony put software on my system that uses techniques commonly used by malware to mask its presence, the software is poorly written and provides no means for uninstall. Worse, most users that stumble across the cloaked files with a RKR scan will cripple their computer if they attempt the obvious step of deleting the cloaked files.
...
I doubted that the files had any version information, but ran my Sigcheck utility on them anyway. To my surprise, the majority did have identifying product, file and company strings. I had already recognized Dbghelp.dll and Unicows.dll as Microsoft Windows DLLs by their names. The other files claimed to be part of the “Essential System Tools” product from a company called “First 4 Internet”
...
I Googled the company name and came across this article, confirming the fact that they have deals with several record companies, including Sony, to implement Digital Rights Management (DRM) software for CDs.
The DRM reference made me recall having purchased a CD recently that can only be played using the media player that ships on the CD itself and that limits you to at most 3 copies. I scrounged through my CD’s and found it, Sony BMG’s Get Right with the Man (the name is ironic under the circumstances) CD by the Van Zant brothers.
...
At that point I knew conclusively that the rootkit and its associated files were related to the First 4 Internet DRM software Sony ships on its CDs. Not happy having underhanded and sloppily written software on my system I looked for a way to uninstall it. However, I didn’t find any reference to it in the Control Panel’s Add or Remove Programs list, nor did I find any uninstall utility or directions on the CD or on First 4 Internet’s site. I checked the EULA and saw no mention of the fact that I was agreeing to have software put on my system that I couldn't uninstall. Now I was mad.
I deleted the driver files and their Registry keys, stopped the $sys$DRMServer service and deleted its image, and rebooted. As I was deleting the driver Registry keys under HKLM\System\CurrentControlSet\Services I noted that they were either configured as boot-start drivers or members of groups listed by name in the HKLM\System\CurrentControlSet\SafeBoot subkeys, which means that they load even in Safe Mode, making system recovery extremely difficult if any of them have a bug that prevents the system from booting.
When I logged in again I discovered that the CD drive was missing from Explorer. Deleting the drivers had disabled the CD. Now I was really mad.
...
I opened Device Manager, displayed the properties for my CD-ROM device, and saw one of the cloaked drivers, Crater.sys (another ironic name, since it had ‘cratered’ my CD)
...
Filter registrations are stored in the Registry under HKLM\System\CurrentControlSet\Enum so I opened Regedit and searched for $sys$ in that key. I found the entry configuring the CD’s lower filter.
I deleted the entry, but got an access-denied error. Those keys have security permissions that only allow the Local System account to modify them, so I relaunched Regedit in the Local System account using PsExec: psexec –s –i –d regedit.exe. I retried the delete, succeeded, and searched for $sys$ again. Next I found an entry configuring another one of the drivers, Cor.sys (internally named Corvus), as an upper filter for the IDE channel device and also deleted it. I rebooted and my CD was back.
The entire experience was frustrating and irritating. Not only had Sony put software on my system that uses techniques commonly used by malware to mask its presence, the software is poorly written and provides no means for uninstall. Worse, most users that stumble across the cloaked files with a RKR scan will cripple their computer if they attempt the obvious step of deleting the cloaked files.
[Comment about the EULA]
Note that there's no mention of a rootkit or the inability to uninstall or delete the software (in fact, there's a reference to being able to do so).
Note that there's no mention of a rootkit or the inability to uninstall or delete the software (in fact, there's a reference to being able to do so).
Comment