TROJ_DROPPER.UFC
Trojan-Banker.Win32.Banbra.aywh (Kaspersky); Trojan horse Generic33.ABOC (AVG)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It disables Task Manager, Registry Editor, and Folder Options.
TECHNICAL DETAILS
486,912 bytes
EXE
No
31 May 2013
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\explorer\
Browser Helper Objects\{2A28FA45-4193-4FE2-B231-57B289753F9E}
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
HKEY_CLASSES_ROOT\CLSID\{2A28FA45-4193-4FE2-B231-57B289753F9E}
HKEY_CLASSES_ROOT\CLSID\{2A28FA45-4193-4FE2-B231-57B289753F9E}\
InprocServer32
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\Ext\
Settings\{2A28FA45-4193-4FE2-B231-57B289753F9E}
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Ext\CLSID
HKEY_CURRENT_USER\SOFTWARE\Policies\
Microsoft\Internet Explorer\Control Panel
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2A28FA45-4193-4FE2-B231-57B289753F9E}\InprocServer32
ThreadingModel = "Apartment"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Ext\CLSID
{2A28FA45-4193-4FE2-B231-57B289753F9E} = "1"
HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
Connection Settings = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "http://www.{BLOCKED}tyverif.com/xvs.dat"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Connections
DefaultConnectionSettings = "{random values}"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Connections
SavedLegacySettings = "{random values}"
(Note: The default value data of the said registry entry is {random values}.)
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
SecurityCRT = "Wscript.exe %User Profile%\Application Data\certificate.vbs"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
SecurityCRT = "Wscript.exe %User Profile%\Application Data\serialconfirm.vbs"
Dropping Routine
This Trojan drops the following files:
- %User Profile%\nt.txt
- %User Profile%\sys.txt
- %System Root%\Documents and Settings\All Userssys32.txt
- %User Profile%\0
- %User Temp%\1376.tmp
- %User Temp%\1253.tmp
- %User Temp%\2801.tmp
- %User Profile%\tbarone001.dll
- %User Profile%\Application Data\certificate.vbs
- %User Profile%\Application Data\serialconfirm.vbs
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Close all opened browser windows
Step 3
Enable Registry Editor, Task Manager, and Folder options
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\Microsoft\Windows\CurrentVersion\Policies\Explorer
- Run
- In HKEY_CLASSES_ROOT\CLSID
- {2A28FA45-4193-4FE2-B231-57B289753F9E}
- In HKEY_CLASSES_ROOT\CLSID\{2A28FA45-4193-4FE2-B231-57B289753F9E}
- InprocServer32
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\Ext\Settings
- {2A28FA45-4193-4FE2-B231-57B289753F9E}
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Ext
- CLSID
- In HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Internet Explorer
- Control Panel
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_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{2A28FA45-4193-4FE2-B231-57B289753F9E}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Ext\CLSID
- {2A28FA45-4193-4FE2-B231-57B289753F9E} = "1"
- In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
- Connection Settings = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- AutoConfigURL = "http://www.{BLOCKED}tyverif.com/xvs.dat"
Step 6
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections
- From: DefaultConnectionSettings = "{random values}"
To: DefaultConnectionSettings = ""{random values}""
- From: DefaultConnectionSettings = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections
- From: SavedLegacySettings = "{random values}"
To: SavedLegacySettings = ""{random values}""
- From: SavedLegacySettings = "{random values}"
Step 7
Search and delete these components
- %User Profile%\nt.txt
- %User Profile%\sys.txt
- %System Root%\Documents and Settings\All Userssys32.txt
- %User Profile%\0
- %User Temp%\1376.tmp
- %User Temp%\1253.tmp
- %User Temp%\2801.tmp
- %User Profile%\tbarone001.dll
- %User Profile%\Application Data\certificate.vbs
- %User Profile%\Application Data\serialconfirm.vbs
Step 8
Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPER.UFC. 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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