BKDR_FARFLI.DAA
Trojan.Gen (Symantec); Backdoor:Win32/Farfli.O (Microsoft); BackDoor-DVB (Mcafee); Troj/Farfli-Gen (Sophos)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
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.
TECHNICAL DETAILS
12,473,344 bytes
DLL
No
31 Oct 2011
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 copies of itself into the affected system:
- %Program Files%\Common Files\Acucpbjdn.jpg
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)
It drops the following non-malicious file:
- C:\Net-Temp.ini
Autostart Technique
This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ebqfei Erogvuim Iet\Parameters
ServiceDll = %Program Files%\Common Files\Acucpbjdn.jpg
Other System Modifications
This backdoor adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Ebqfei Erogvuim Iet
HKEY_LOCAL_MACHINE\SOFTWARE\{random numbers}
HKEY_CURRENT_USER\NetSubKey
HKEY_USERS\.DEFAULT\NetSubKey
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
imgsvc = {user defined} Ebqfei Erogvuim Iet
(Note: The default value data of the said registry entry is {user defined}.)
Backdoor Routine
This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}ddos.3322.org
Other Details
This backdoor connects to the following possibly malicious URL:
- http://www.{BLOCKED}u.com/ip.txt
- http://www.{BLOCKED}aibinzang.com/zc2.htm
SOLUTION
9.200
8.538.01
31 Oct 2011
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
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- Ebqfei Erogvuim Iet
- Ebqfei Erogvuim Iet
- In HKEY_LOCAL_MACHINE\SOFTWARE
- {random numbers}
- {random numbers}
- In HKEY_CURRENT_USER
- NetSubKey
- NetSubKey
- In HKEY_USERS\.DEFAULT
- NetSubKey
- NetSubKey
Step 4
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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
- From: imgsvc = {user defined} Ebqfei Erogvuim Iet
To: imgsvc = {user defined}
- From: imgsvc = {user defined} Ebqfei Erogvuim Iet
Step 5
Search and delete this file
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_FARFLI.DAA. 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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