BKDR_OBFUSCA.HHZ
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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 injects its dropped file/component to specific processes.
TECHNICAL DETAILS
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 drops the following file(s)/component(s):
- %User Temp%\autoexec.bat
- {folder where malware is dropped or executed}\110805_ΖûEÎ’YEz•¨ŽQlŽ‘—¿W\110805_ΖûEÎ’YEz•¨ŽQlŽ‘—¿W.ppt
- %User Temp%\tabcteng.dll
(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.)
It creates the following folders:
- {folder where malware is dropped or executed}\110805_ΖûEÎ’YEz•¨ŽQlŽ‘—¿
It injects its dropped file/component to the following processes:
- IEXPLORE.EXE
Autostart Technique
This backdoor modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Netman\Parameters
ServiceDll = "%User Temp%\tabcteng.dll"
(Note: The default value data of the said registry entry is %SystemRoot%\System32\netman.dll.)
Other System Modifications
This backdoor modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Netman
Start = "2"
(Note: The default value data of the said registry entry is 3.)
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Restore this modified 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netman
- From: Start = "2"
To: Start = "3"
- From: Start = "2"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netman\Parameters
- From: ServiceDll = "%User Temp%\tabcteng.dll"
To: ServiceDll = "%SystemRoot%\System32\netman.dll"
- From: ServiceDll = "%User Temp%\tabcteng.dll"
Step 4
Search and delete this folder
- {folder where malware is dropped or executed}\110805_ΖûEÎ’YEz•¨ŽQlŽ‘—¿
Step 5
Search and delete these files
- %User Temp%\autoexec.bat
- %User Temp%\tabcteng.dll
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_OBFUSCA.HHZ. 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.