TROJ_FRAUDLO.BAC
W32/FraudLoad.MK!tr (Fortinet)
Windows 2000, XP, Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This Trojan may be dropped by other malware.
It adds registry entries to enable its automatic execution at every system startup.
TECHNICAL DETAILS
Arrival Details
This Trojan may be dropped by other malware.
Installation
This Trojan drops the following copies of itself into the affected system:
- %User Profile%\Application Data\dwm.exe
- %User Profile%\Application Data\Microsoft\conhost.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It drops the following files:
- %User Profile%\Application Data\0786.FAD
- %User Temp%\csrss.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "explorer.exe,%User Profile%\Application Data\dwm.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
conhost = "%User Profile%\Application Data\Microsoft\conhost.exe"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
WIndows\CurrentVersion\Internet Settings
ProxyServer = "http=127.0.0.1:49980"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = 1
(Note: The default value data of the said registry entry is 0.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%User Temp%\csrss.exe"
(Note: The default value data of the said registry entry is "".)
SOLUTION
Step 1
For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Identify and delete files detected as TROJ_FRAUDLO.BAC using either the Startup Disk or Recovery Console
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 NT\CurrentVersion\Winlogon
- Shell = explorer.exe,%User Profile%\Application Data\dwm.exe
- Shell = explorer.exe,%User Profile%\Application Data\dwm.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- conhost = %User Profile%\Application Data\Microsoft\conhost.exe
- conhost = %User Profile%\Application Data\Microsoft\conhost.exe
- In HKEY_CURRENT_USER\Software\Microsoft\WIndows\CurrentVersion\Internet Settings
- ProxyServer = http=127.0.0.1:49980
- ProxyServer = http=127.0.0.1:49980
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- From: ProxyEnable=1
To: ProxyEnable=0
- From: ProxyEnable=1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- From: load=%User Temp%\csrss.exe
To: load=
- From: load=%User Temp%\csrss.exe
Step 5
Search and delete this file
%User Temp%\csrss.exe
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_FRAUDLO.BAC 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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