- Threat Encyclopedia
- Malware
- BKDR_VAWTRAK.SMN
TrojanDropper:Win32/Vawtrak.A(Microsoft),Trojan-PSW.Win32.Tepfer.tujc(Kaspersky),a variant of Win32/Kryptik.CAAI trojan(NOD32)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Downloaded from the Internet, Dropped by other malware
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.
It is injected into all running processes to remain memory resident.
It executes commands from a remote malicious user, effectively compromising the affected system.
Varies
DLL
Yes
17 May 2014
Steals information
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 is injected into all running processes to remain memory resident.
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{malware filename} = "regsvr32.exe "{malware path}\{malware filename}.{malware extension name}""
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{GUID 1}
HKEY_CLASSES_ROOT\CLSID\{GUID 2}
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID 1}
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID 2}
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
NoProtectedModeBanner = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
TabProcGrowth = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
2500 = "3"
HKEY_CLASSES_ROOT\CLSID\{GUID 1}
#cert = "{hex value}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID 1}
#cert = "{hex value}"
HKEY_CLASSES_ROOT\CLSID\{GUID 2}
{GUID 3} = "{hex value}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID 2}
{GUID 3} = "{hex value}"
HKEY_CLASSES_ROOT\CLSID\{GUID 2}
{GUID 4} = "{encrypted form of config data}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{GUID 2}
{GUID 4} = "{encrypted form of config data}"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
It connects to the following URL(s) to send and receive commands from a remote malicious user:
Information Theft
This backdoor attempts to steal stored account information used in the following installed File Transfer Protocol (FTP) clients or file manager software:
It attempts to steal stored email credentials from the following:
It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:
NOTES:
This backdoor checks for the presence of the following security-related directories in %Program Files% and %All Users Profile%\Application Data:
Once it finds one of the AV installations mentioned above, it then creates the following registry entries to force the AV installation to run under restricted user privileges:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers\0\Paths\{generated GUID for the AV software}
ItemData = "{AV software path}"
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers\0\Paths\{generated GUID for the AV software}
SaferFlags = "0"
It can only perform its intended routine once it is injected in the following processes:
The configuration data that is received as of this writing contains the banking and credit card institutions in which it monitors.
The config data also contains the code for web injects which points to the following URL:
9.700
10.809.00
22 May 2014
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
Restart in Safe Mode
Step 3
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.
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_VAWTRAK.SMN. 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.