BKDR_SINOWAL.COP
BDS/Sinowal.thd (Antivir), W32/Sinowal.THD!tr.bdr (Fortinet), Backdoor.Win32.Sinowal (Ikarus), Backdoor.Sinowal (VBA32)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor may be downloaded by other malware/grayware/spyware from remote sites.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
Arrival Details
This backdoor may be downloaded by other malware/grayware/spyware from remote sites.
Installation
This backdoor drops the following files:
- %All Users Profile%\Application Data\{random number 1}\{random number}.dat - contains hex value of its file name
- %All Users Profile%\Application Data\{random number 1}\{random number}.dll - contains hex value of its file name
- %All Users Profile%\Application Data\{random number 1}\{dat name}.dat - config file
- %All Users Profile%\Application Data\{random number 1}\{dll name}.dll - also detected as BKDR_SINOWAL.COP
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- PJYTYOCEBHBSCAJFEJTLTHSCBHEBY
- KDACHIQCQPAXYBVCXUPYXFYCSQWR
- KDACHIQCQPAXYBVCXUPYXFYCSQWR-{number}
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CLASSES_ROOT\CLSID\{GUID}\
InprocServer32
(Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID}\InprocServer32
(Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\ShellServiceObjectDelayLoad
{value name} = "{GUID}"
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Windows
LoadAppInitDLLs = "1"
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Windows
RequireSignedAppInit_DLLs = "0"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Download arbitrary files
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}stingmultiformat.org/search2?fr=altavista&itag=ody&q=443b40b41d25b91dd9a4104278083c14%2Cf4f535b835f5429b&kgs=1&kls=0&p={parameter}
- http://{BLOCKED}.{BLOCKED}.109.201/search2?fr=altavista&itag=ody&q=443b40b41d25b91dd9a4104278083c14%2Cf4f535b835f5429b&kgs=1&kls=0&p={parameter}
- http://www.{BLOCKED}rtsgm.com/search2?fr=altavista&itag=ody&q=443b40b41d25b91dd9a4104278083c14%2Cf4f535b835f5429b&kgs=1&kls=0&p={parameter}
It posts the following information to its command and control (C&C) server:
- List of running processes
- Applications installed in the system (found in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall)
As of this writing, the said servers are currently inaccessible.
NOTES:
This backdoor suspends the thread of Trusteer Rapport program if it finds the said thread running in the processes of the following browsers:
- opera.exe
- chrome.exe
- firefox.exe
- iexplore.exe
It displays a message box with the following contents if the file avgui.exe is running in the system:
Title: Thank you
Message: Thank you for using AVG Product!
{dll name} can be any of the following:
- mswd
- mscc
- msdr
- msdd
- msee
- wsse
- msseedir
- lmbd
- mmdd
{dat name} can be any of the following:
- jdlr
- elct
- nudr
- werr
- qnud
- xdor
- ccdxmmde
- vvve
- kdkd
- colu
- uloc
- drss
- rrxx
- du44
- xes2
- ii33
- ned9
- i3u4
{GUID} can be any of the following:
- {A12BEDCC-A901-4203-B4F2-ADCB957D1887}
- {212B3DCC-A901-4203-B4F2-ADCB957D1887}
- {312BFDCE-A901-4203-B4F2-ADCB957D1887}
- {F12BE2CC-A901-4203-B4F2-ADCB957D1887}
- {312BED3C-A901-4203-B4F2-ADCB957D1887}
- {118BEDCC-A901-4203-B4F2-ADCB957D1887}
{value name} can be any of the following:
- MSCPY
- CopierMircosoft
- MSCopy
- MicrosoftCopy
- WindowsCopy
- Copier
This backdoor executes its DLL component by using the following command:
%System%\cmd.exe /c %System%\regsvr32.exe /s "%All Users Profile%\Application Data\{dll name}.dll"
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Scan your computer with your Trend Micro product and note files detected as BKDR_SINOWAL.COP
Step 3
Identify and delete files detected as BKDR_SINOWAL.COP using the Recovery Console
Step 4
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CLASSES_ROOT\CLSID\{GUID}\InprocServer32
- (Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- (Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- In HKEY_CURRENT_USER\Software\Classes\CLSID\{GUID}\InprocServer32
- (Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- (Default) = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellServiceObjectDelayLoad
- {value name} = "{GUID}"
- {value name} = "{GUID}"
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows
- AppInit_DLLs = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- AppInit_DLLs = "%All Users Profile%\Application Data\{random number 1}\{dll name}.dll"
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows
- LoadAppInitDLLs = "1"
- LoadAppInitDLLs = "1"
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Windows
- RequireSignedAppInit_DLLs = "0"
- RequireSignedAppInit_DLLs = "0"
Step 5
Search and delete these files
- %All Users Profile%\Application Data\{random number 1}\{random number}.dat - contains hex value of its file name
- %All Users Profile%\Application Data\{random number 1}\{random number}.dll - contains hex value of its file name
- %All Users Profile%\Application Data\{random number 1}\{dat name}.dat - config file
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_SINOWAL.COP. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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