BKDR_ESILE.SMAP
a variant of Win32/Elsentric.C trojan (NOD32), W32/Agent.POF!tr (FORTINET)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
65,024 bytes
DLL
No
Arrival Details
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This backdoor drops the following files:
- %Application Data%\Microsoft\{variable folder name}\{variable file name 1}.exe
- %Application Data%\Microsoft\{variable folder name}\{variable file name 2}.dll
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It creates the following folders:
- %Application Data%\Microsoft\{variable folder name}\
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Autostart Technique
This backdoor registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry entries:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
Type = "20"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
Start = "2"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
ErrorControl = "1"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
ImagePath = "%SystemRoot%\System32\svchost.exe -k mssvc"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
DisplayName = "MS Software Shadow Provider"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
ObjectName = "LocalSystem"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
Description = "Manages software-based volume shadow taken by the Volume Shadow service. If this service is stopped, software based volume shadow cannot be manages. If this service is disabled, any service that explicitly depend on it will fail to start."
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Parameters
ServiceMain = ESEntry
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Parameters
ServiceDll = "%Application Data%\Microsoft\{variable folder name}\{variable file name 2}.dll"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Security
Security = "(hex values)"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Enum
0 = "Root\LEGACY_SWPVC\0000"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Enum
Count = "1"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Enum
NextInstance = "1"
It registers its dropped component as a system service to ensure its automatic execution at every system startup. It does this by creating the following registry keys:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Parameters
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Security
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SwPvc\Enum
Other System Modifications
This backdoor adds the following registry entries:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Svchost
mssvc = "SwPvc"
Other Details
This backdoor connects to the following possibly malicious URL:
- www.{BLOCKED}oahau.com
- {BLOCKED}6.{BLOCKED}1.237.59
NOTES:
{variable folder name} may have the following values:
- IMGP8_1
- ime
{variable file name 1} may have the following values:
- imjpmig
- imekrmig
{variable file name 2} may have the following values
- imekrcic
- imejpcic
SOLUTION
9.700
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
Step 4
Delete this registry key
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
- SwPvc
- SwPvc
Step 5
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_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Svchost
- mssvc = "SwPvc"
- mssvc = "SwPvc"
Step 6
Search and delete these files
- %Application Data%\Microsoft\{variable folder name}\{variable file name 1}.exe
- %Application Data%\Microsoft\{variable folder name}\{variable file name 1}.dll
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ESILE.SMAP. 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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