WORM_DORKBOT.APP
Worm:Win32/Dorkbot.I(Microsoft), W32/Ngrbot.WNH!worm(Fortinet), Worm.Win32.Ngrbot(Ikarus), a variant of Win32/Kryptik.BQWW trojan(Eset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
TECHNICAL DETAILS
106,496 bytes
EXE
Yes
09 Jan 2014
Arrival Details
This worm 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 files:
- {Drive letter}:\{folder/file name}.lnk - if folder/file exists
It drops the following copies of itself into the affected system:
- %User Temp%\Adobe\Reader_sl.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It creates the following folders:
- %Application Data%\c732100
- %User Temp%\Adobe
- %User Temp%\c732100
(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.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp 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
Adobe System Incorporated = "%User Temp%\Adobe\Reader_sl.exe"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- {Drive letter}:\YwxbMUAEJlpXuef.exe
Download Routine
This worm saves the files it downloads using the following names:
- %Application Data%\{random digit}.exe
(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.)
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
Other Details
This worm connects to the following URL(s) to get the affected system's IP address:
- api.wipmania.com
It attempts to access the following websites to download files, which are possibly malicious:
- http://{BLOCKED}.{BLOCKED}.53.178/6542new6.exe
- http://{BLOCKED}.{BLOCKED}.8.53/6542new6.exe
- http://{BLOCKED}.{BLOCKED}.8.53/use.exe
- http://{BLOCKED}.{BLOCKED}.8.53/bren.exe
- http://{BLOCKED}{BLOCKED}.8.53/vse.exe
NOTES:
This worm creates .LNK (shortcut) files using folder/file names found in removable drives. It then hides the original folder/file tricking users to click .LNK files. This .LNK files point out to a dropped copy of itself in the removable drive.
SOLUTION
9.700
10.544.08
17 Jan 2014
10.545.00
17 Jan 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.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Adobe System Incorporated = "%User Temp%\Adobe\Reader_sl.exe"
- Adobe System Incorporated = "%User Temp%\Adobe\Reader_sl.exe"
Step 4
Search and delete these folders
- %Application Data%\c732100
- %User Temp%\Adobe
- %User Temp%\c732100
Step 5
Search and delete these files
- %Application Data%\{random digit}.exe
- {Drive letter}:\{folder/file name}.lnk
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DORKBOT.APP. 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.