BKDR_VAWTRAK.DSW
Backdoor:Win32/Vawtrak.F (Microsoft)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
285,064 bytes
DLL
Yes
01 Nov 2014
Connects to URLs/IPs, Compromises system security
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.
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\{CLSID 1}
HKEY_CLASSES_ROOT\CLSID\{CLSID 2}
HKEY_CURRENT_USER\Software\Classes\
CLSID\{CLSID 1}
HKEY_CURRENT_USER\Software\Classes\
CLSID\{CLSID 2}
It adds the following registry entries:
HKEY_CLASSES_ROOT\CLSID\{CLSID 2}
{CLSID 4} = "{encrypted form of config data}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{CLSID 2}
{CLSID 4} = "{encrypted form of config data}"
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\{CLSID 1}
#cert = "{hex value}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{CLSID 1}
#cert = "{hex value}"
HKEY_CLASSES_ROOT\CLSID\{CLSID 2}
{CLSID 3} = "{hex value}"
HKEY_CURRENT_USER\Software\Classes\
CLSID\{CLSID 2}
{CLSID 3} = "{hex value}"
Propagation
This backdoor does not have any propagation routine.
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Receive config data it will use for its information stealing routine
- Update itself
- Download and execute files
- List active processes
- Perform remote shell
- Execute file
- Keylog
- Capture Screenshot
- Monitor sound
- Start/Stop process (iexplore.exe, firefox.exe, outlook.exe, explorer.exe, cmd.exe, taskmgr.exe)
- Inject to process
- Get clipboard data
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{malicious domain}/viewforum.php?f={value}&sid={value}
- http://{malicious domain}/posting.php?mode=reply&f={value}&t={value}&sid={value}
- http://{malicious domain}/posting.php?mode=post&f={value}&sid={value}
Information Theft
This backdoor s configuration file contains the following information:
- websites to monitor
- URL source of the codes to use for web injects
It attempts to steal stored account information used in the following installed File Transfer Protocol (FTP) clients or file manager software:
- 3D-FTP
- AceBIT
- AceFTP
- ALFTP
- BitKinex
- BlazeFtp
- BulletProof FTP
- ClassicFTP
- CoffeeCup Software
- Cyberduck
- DeluxeFTP
- Directory Opus
- EasyFTP
- ExpanDrive
- FarManager
- FFFTP
- FileZilla
- FlashFXP
- Fling FTP
- FreshFTP
- FTP Commander
- FTP Explorer
- FTP Navigator
- FTPGetter
- FTPNow
- FTPRush
- FTPShell
- FTPVoyager
- FTPWare
- GlobalSCAPE CuteFTP 6 Home
- GlobalSCAPE CuteFTP 7 Home
- GlobalSCAPE CuteFTP 8 Home
- GlobalSCAPE CuteFTP
- GlobalSCAPE CuteFTP 8 Professional
- GlobalSCAPE CuteFTP 6 Professional
- GlobalSCAPE CuteFTP 7 Professional
- GlobalSCAPE CuteFTP Lite
- GlobalSCAPE CuteFTP Pro
- GoFTP
- LeapFTP
- LeechFTP
- LinasFTP
- My FTP
- NetDrive
- NetSarang
- NexusFile
- NovaFTP
- PuTTY
- RhinoSoft
- Robo-FTP
- SecureFX
- SmartFTP
- SoftX FTP
- Staff-FTP
- Titan FTP
- Total Commander
- TurboFTP
- UltraFXP
- WinFTP
- WinSCP
- WS_FTP
It attempts to steal stored email credentials from the following:
- IncrediMail
- Outlook
- PocoMail
- The Bat!
- Thunderbird
- Windows Live Mail
- Windows Mail
It attempts to get stored information such as user names, passwords, and hostnames from the following browsers:
- Epic Browser
- Flock
- K-Meleon
- Mozilla Firefox
- SeaMonkey
NOTES:
The malicious domains mentioned above are the following:
- {BLOCKED}.{BLOCKED}.184.239
- {BLOCKED}is.com
- {BLOCKED}ng.com
- {BLOCKED}rda.com
- {BLOCKED}ka.com
- {BLOCKED}.{BLOCKED}.192.106
- {BLOCKED}nova.com
- {BLOCKED}ka.com
- {BLOCKED}.{BLOCKED}.192.110
- {BLOCKED}ag.com
- {BLOCKED}.{BLOCKED}.51.216
- {BLOCKED}ixand.net
- {BLOCKED}.{BLOCKED}.233.91
- {BLOCKED}ad.com
- {BLOCKED}lon.com
- {BLOCKED}.{BLOCKED}.233.97
- {BLOCKED}3.com
- {BLOCKED}z.com
- {BLOCKED}lpane.com
As of this writing, only {BLOCKED}ad.com is accessible.
It checks for the presence of the following security-related directories in %Program Files% and %All Users Profile%\Application Data:
- a-squared Anti-Malware
- a-squared HiJackFree
- Agnitum
- Alwil Software
- AnVir Task Manager
- ArcaBit
- AVAST Software
- AVG
- avg8
- Avira GmbH
- Avira
- BitDefender
- BlockPost
- Common Files\Doctor Web
- Common Files\G DATA
- Common Files\P Tools
- Common Files\Symantec Shared
- DefenseWall
- DefenseWall HIPS
- Doctor Web
- DrWeb
- ESET
- f-secure
- FRISK Software
- G DATA
- K7 omputing
- Kaspersky Lab Setup Files
- Kaspersky Lab
- Lavasoft
- Malwarebytes
- Malwarebytes' Anti-Malware
- McAfee
- McAfee.com
- Microsoft Security Client
- Microsoft Security Essentials
- Microsoft\Microsoft Antimalware
- Norton AntiVirus
- Online Solutions
- P Tools Internet Security
- P Tools
- Panda Security
- Positive Technologies
- Sandboxie
- Security Task Manager
- Spyware Terminator
- Sunbelt Software
- Symantec
- Trend Micro
- UAenter
- Vba32
- Xore
- Zillya Antivirus
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:
- chrome.exe
- explorer.exe
- firefox.exe
- iexplore.exe
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.700
11.253.00
03 Nov 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
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
Scan your computer with your Trend Micro product and note files detected as BKDR_VAWTRAK.DSW
Step 4
Restart in Safe Mode
Step 5
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.
- In HKEY_CLASSES_ROOT\CLSID
- {CLSID 1}
- {CLSID 1}
- In HKEY_CLASSES_ROOT\CLSID
- {CLSID 2}
- {CLSID 2}
- In HKEY_CURRENT_USER\Software\Classes\CLSID
- {CLSID 1}
- {CLSID 1}
- In HKEY_CURRENT_USER\Software\Classes\CLSID
- {CLSID 2}
- {CLSID 2}
Step 6
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {malware filename} = "regsvr32.exe "{malware path}\{malware filename}.{malware extension name}""
- {malware filename} = "regsvr32.exe "{malware path}\{malware filename}.{malware extension name}""
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- NoProtectedModeBanner = "1"
- NoProtectedModeBanner = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- TabProcGrowth = "0"
- TabProcGrowth = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\3
- 2500 = "3"
- 2500 = "3"
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_VAWTRAK.DSW. 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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