WORM_DORKBOT.PW
W32/AutoRun.EXQN!worm (Fortinet), Worm.Win32.AutoRun.exqn (Kaspersky), Worm:Win32/Dorkbot.I (Microsoft)
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: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives by connecting affected removable drives to a system. It 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
123,904 bytes
EXE
Yes
11 Apr 2013
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It 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 worm drops the following copies of itself into the affected system:
- %Application Data%\{random}.exe
- %Application Data%\Microsoft\{random file name}.exe
- %Application Data%\ScreenSaverPro.scr
- %Application Data%\temp.bin
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random file name} = "%Application Data%\Microsoft\{random file name}.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Screen Saver Pro 3.1 = "%Application Data%\ScreenSaverPro.scr"
Propagation
This worm creates the following folders in all removable drives:
- {Drive Letter}:\.Trashes
It drops the following copy(ies) of itself in all removable drives:
- {Drive Letter}:\.Trashes\b3fdadef.com
Dropping Routine
This worm drops the following files:
- {Drive Letter}:\.Trashes.lnk
- {Drive Letter}:\{folder name}.lnk - if the removable drive contains folders
- {Drive Letter}:\{file name}.lnk - if the removable drive contains files
- {Drive Letter}:\{random}.exe
- {Drive Letter}:\_[$]_TESTFILE_[$]_
- {Drive Letter}:\.Trashes\Desktop.ini
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}.{BLOCKED}.246.160/18.exe
- http://{BLOCKED}.{BLOCKED}.246.44/17.exe
- http://{BLOCKED}.{BLOCKED}.246.44/av.txt
- http://{BLOCKED}.{BLOCKED}.246.55/17.exe
- http://{BLOCKED}.{BLOCKED}.246.55/av.txt
SOLUTION
9.300
9.946.04
11 Apr 2013
9.947.00
12 Apr 2013
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 WORM_DORKBOT.PW
Step 3
Restart in Safe Mode
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Screen Saver Pro 3.1 = "%Application Data%\ScreenSaverPro.scr"
- Screen Saver Pro 3.1 = "%Application Data%\ScreenSaverPro.scr"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random file name} = "%Application Data%\Microsoft\{random file name}.exe"
- {random file name} = "%Application Data%\Microsoft\{random file name}.exe"
Step 5
Search and delete this folder
- {Drive Letter}:\.Trashes
Step 6
Search and delete these files
- {Drive Letter}:\_[$]_TESTFILE_[$]_
- {Drive Letter}:\.Trashes.lnk
- {Drive Letter}:\{folder name}.lnk
- {Drive Letter}:\{file name}.lnk
- {Drive Letter}:\{random}.exe
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DORKBOT.PW. 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.
Did this description help? Tell us how we did.