BKDR_VAWTRAK.B
Backdoor:Win32/Vawtrak.A (Microsoft), Backdoor.Win32.Vawtrak (Ikarus)
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 from remote sites. It may be dropped by other malware. It arrives as a component bundled with malware/grayware packages.
It is injected into all running processes to remain memory resident.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
Arrival Details
This backdoor may be downloaded by the following malware/grayware from remote sites:
- TROJ_DLOADR.AAJ
It may be dropped by other malware.
It arrives as a component bundled with malware/grayware packages.
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 /s "{malware path}\{malware filename}.dll""
Other System Modifications
This backdoor adds the following registry keys:
ADDED REGISTRY HKEY_CURRENT_USER\Software\AppDataLow
HKEY_CURRENT_USER\Software\AppDataLow\
{random key 1}
HKEY_CURRENT_USER\Software\AppDataLow\
{random key 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"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Keylog
- Capture screenshots
- Start process (iexplore.exe, firefox.exe, outlook.exe, explorer.exe, cmd.exe, taskmgr.exe)
- Inject to process
- Perform remote shell
- Update Itself
- List processes
- Download and execute files
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}.188.50/post.aspx?forumID={random digit}
- http://{BLOCKED}.188.50/forumdisplay.php?fid={random digit}
- http://{BLOCKED}.56.247
- http://{BLOCKED}n.com.tw
- http://{BLOCKED}g.com.tw
Information Theft
This backdoor 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:
This backdoor can only perform its intended routine once it is injected in the following processes:
- chrome.exe
- explorer.exe
- firefox.exe
- iexplore.exe
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
Remove the malware/grayware file that dropped/downloaded BKDR_VAWTRAK.B
- TROJ_DLOADR.AAJ
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.
- In HKEY_CURRENT_USER\Software
- AppDataLow
- AppDataLow
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_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 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_VAWTRAK.B. 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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