BKDR_ZACESS.SMQQ
Windows 2000, Windows XP, Windows Server 2003

Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
This backdoor terminates processes which can compromise system security. It also patches a file that subsequently becomes malicious.
This backdoor arrives via peer-to-peer (P2P) shares. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be dropped by other malware.
It connects to a website to send and receive information.
TECHNICAL DETAILS
192,512 bytes
DLL
Yes
06 Jul 2012
Connects to URLs/IPs, Terminates processes, Patches files
Arrival Details
This backdoor arrives via peer-to-peer (P2P) shares.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It may be dropped by the following malware:
- BKDR_ZACCESS.KP
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\CLSID\{42aedc87-2188-41fd-b9a3-0c966feabec1}\
InprocServer32
ThreadingModel = "Both"
HKEY_CURRENT_USER\CLSID\{42aedc87-2188-41fd-b9a3-0c966feabec1}\
InprocServer32
(Default) = "%Application Data%\{GUID}\n."
Other System Modifications
This backdoor modifies the following registry entries:
HKEY_CLASSES_ROOT\CLSID\{F3130CDB-AA52-4C3A-AB32-85FFC23AF9C1}\
InprocServer32
(Default) = "\.\globalroot\systemroot\Installer\{GUID}\n."
(Note: The default value data of the said registry entry is %System%\wbem\wbemess.dll.)
Backdoor Routine
This backdoor connects to the following websites to send and receive information:
- http://{BLOCKED}s.{BLOCKED}g.com
Process Termination
This backdoor terminates the following processes if found running in the affected system's memory:
- MsMpSvc
- windefend
- SharedAccess
- iphlpsvc
- wscsvc
- mpssvc
- bfe
- SecurityCenter
- Wscnotify.exe
- MSASCui.exe
- MpCmdRun.exe
- MisSrv.exe
- msseces.exe
- wsctfy.exe
Other Details
This backdoor requires the existence of the following files to properly run:
- %User Temp%\InstallFlashPlayer.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
NOTES:
It connects to its C&C server using UDP connection.
It is a .DLL file, which is executed by %User Temp%\InstallFlashPlayer.exe.
It patches %System%\services.exe and saves the original copy in %System%\Winsxs\Backup\services.exe.
- Patched 64-bit %System%\services.exe - detected as PTCH64_ZACCESS.A
- Patched Win7 32-bit %System%\services.exe - detected as PTCH_ZACCESS.A
The modified registry ensures that the malware is loaded instead of %System%\wbem\wbemess.dll, which is related to Web Browser Control.
The following files, which are dropped by the main malware BKDR_ZACCESS.KP, are used by BKDR_ZACESS.SMQQ in registry entries to enable automatic execution of the malware at every system startup:
- %Application Data%\{GUID}\n.
- \.\globalroot\systemroot\Installer\{GUID}\n.
where \.\globalroot\systemroot is equivalent to %Windows%
SOLUTION
9.200
9.240.07
06 Jul 2012
9.241.00
06 Jul 2012
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you to allow full scanning of your computer.
Step 2
Remove malware files dropped/downloaded by BKDR_ZACESS.SMQQ
Step 3
Remove the malware/grayware file that dropped/downloaded BKDR_ZACESS.SMQQ