TROJ_DLOADER.USL15VC
Rogue:Win32/FakeRean (Microsoft); FakeAlert-Rena.bh (McAfee); WindowsAVPro!gen1 (Symantec); Trojan.Win32.FakeAV.ixoe (Kaspersky); Trojan.Win32.Rena.bc (v) (Sunbelt); Gen:Variant.Kazy.46372 (FSecure)
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 modifies files, disabling programs and applications from properly running.
It deletes itself after execution.
TECHNICAL DETAILS
296,960 bytes
EXE
Yes
29 Jun 2012
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 adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
340542829 = "%Application Data%\vke.exe"
Other System Modifications
This Trojan modifies the following files:
- %Application Data%\GDIPFONTCACHEV1.DAT
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\.exe
HKEY_CURRENT_USER\.exe\DefaultIcon
HKEY_CURRENT_USER\.exe\shell
HKEY_CURRENT_USER\.exe\shell\
open
HKEY_CURRENT_USER\.exe\shell\
open\command
HKEY_CURRENT_USER\.exe\shell\
runas
HKEY_CURRENT_USER\.exe\shell\
runas\command
HKEY_CURRENT_USER\exefile
HKEY_CURRENT_USER\exefile\DefaultIcon
HKEY_CURRENT_USER\exefile\shell
HKEY_CURRENT_USER\exefile\shell\
open
HKEY_CURRENT_USER\exefile\shell\
open\command
HKEY_CURRENT_USER\exefile\shell\
runas
HKEY_CURRENT_USER\exefile\shell\
runas\command
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DoNotAllowExceptions = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DisableNotifications = "1"
HKEY_CURRENT_USER\.exe
Content Type = "application/x-msdownload"
HKEY_CURRENT_USER\.exe\shell\
open\command
IsolatedCommand = "%1 %*"
HKEY_CURRENT_USER\.exe\shell\
runas\command
IsolatedCommand = "%1 %*"
HKEY_CURRENT_USER\exefile
Content Type = "application/x-msdownload"
HKEY_CURRENT_USER\exefile\shell\
open\command
IsolatedCommand = "%1 %*"
HKEY_CURRENT_USER\exefile\shell\
runas\command
IsolatedCommand = "%1 %*"
HKEY_CURRENT_USER\Software\Microsoft\
Windows
Identity = "42d18fbc"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ctfmon.exe = "%System%\ctfmon.exe"
(Note: The default value data of the said registry entry is %Windows%\system32\ctfmon.exe.)
HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"
(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\anb1.tmp
- %User Temp%\anb2.tmp
- %Application Data%\vke.exe
- %User Temp%\anb3.tmp
- %User Temp%\anb4.tmp
(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.. %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.200
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.
- In HKEY_CURRENT_USER
- .exe
- In HKEY_CURRENT_USER\.exe
- DefaultIcon
- In HKEY_CURRENT_USER\.exe
- shell
- In HKEY_CURRENT_USER\.exe\shell
- open
- In HKEY_CURRENT_USER\.exe\shell\open
- command
- In HKEY_CURRENT_USER\.exe\shell
- runas
- In HKEY_CURRENT_USER\.exe\shell\runas
- command
- In HKEY_CURRENT_USER
- exefile
- In HKEY_CURRENT_USER\exefile
- DefaultIcon
- In HKEY_CURRENT_USER\exefile
- shell
- In HKEY_CURRENT_USER\exefile\shell
- open
- In HKEY_CURRENT_USER\exefile\shell\open
- command
- In HKEY_CURRENT_USER\exefile\shell
- runas
- In HKEY_CURRENT_USER\exefile\shell\runas
- command
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
- 340542829 = "%Application Data%\vke.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DoNotAllowExceptions = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- DoNotAllowExceptions = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- DisableNotifications = "1"
- In HKEY_CURRENT_USER\.exe
- Content Type = "application/x-msdownload"
- In HKEY_CURRENT_USER\.exe\shell\open\command
- IsolatedCommand = "%1 %*"
- In HKEY_CURRENT_USER\.exe\shell\runas\command
- IsolatedCommand = "%1 %*"
- In HKEY_CURRENT_USER\exefile
- Content Type = "application/x-msdownload"
- In HKEY_CURRENT_USER\exefile\shell\open\command
- IsolatedCommand = "%1 %*"
- In HKEY_CURRENT_USER\exefile\shell\runas\command
- IsolatedCommand = "%1 %*"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows
- Identity = "42d18fbc"
Step 5
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\ControlSet001\Services\SharedAccess
- From: Start = "4"
To: Start = ""2""
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- AntiVirusOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallDisableNotify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- FirewallOverride = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- UpdatesDisableNotify = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- From: ctfmon.exe = "%System%\ctfmon.exe"
To: ctfmon.exe = ""%Windows%\system32\ctfmon.exe""
- From: ctfmon.exe = "%System%\ctfmon.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\GDIPlus
- From: FontCachePath = "%Application Data%"
To: FontCachePath = ""%User Profile%\Local Settings\Application Data""
- From: FontCachePath = "%Application Data%"
Step 6
Search and delete these files
- %User Temp%\anb1.tmp
- %User Temp%\anb2.tmp
- %Application Data%\vke.exe
- %User Temp%\anb3.tmp
- %User Temp%\anb4.tmp
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADER.USL15VC. 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.
Step 8
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %Application Data%\GDIPFONTCACHEV1.DAT
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