TROJ_DOFOIL.UKL
TrojanDownloader:Win32/Dofoil.T (Microsoft)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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 may be downloaded by other malware/grayware from remote sites.
It does not have any propagation routine.
It does not have any backdoor routine.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
111,785 bytes
EXE
Yes
16 Feb 2015
Connects to URLs/IPs
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.
It may be downloaded by the following malware/grayware from remote sites:
- TROJ_WERDLOD.D
It may be downloaded from the following remote site(s):
- http://{BLOCKED}bunko.org/wp/wp-content/themes/twentyfourteen/images/vrucimeirxeimurixeuri.exe
Installation
This Trojan drops the following copies of itself into the affected system:
- %Application Data%\{random folder name}\{random file name}.exe
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It adds the following processes:
- svchost.exe
It creates the following folders:
- %Application Data%\{random folder name}
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It injects codes into the following process(es):
- explorer.exe
- svchost.exe
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
{installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Other Details
This Trojan connects to the following URL(s) to check for an Internet connection:
- http://www.msn.com
It deletes the initially executed copy of itself
NOTES:
This Trojan performs infinite sleep if its file name contains the string sample.
It checks all registry data under the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Disk\Enum
It performs infinite sleep if any of the registry data contains any of the following strings:
- sbiedll
- dbghelp
- qemu
- virtual
- vmware
- xen
It connects to the URLs that are found in the following registry entries to trick users that it is a legitimate program:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\{Installed Program}
HelpLink = "{url related to installed program}"
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\{Installed Program}
URLInfoAbout = "{url related to installed program}"
It looks for the window name Shell_TrayWnd and then opens the process associated with the said window to execute its code. This Trojan does this routine to inject its code to svchost.exe, avoiding HIPS detection.
It connects to the following server to receive an arbitrary file:
- http://{BLOCKED}3.{BLOCKED}2.20.14/cartin/image.php
As of this writing, the server returned the following URL:
- http://www.{BLOCKED}gge.at/ta_tools/gate.php?client_id={value}&connected={value}&server_port={value}&debug={value}
However, this URL is idle.
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.700
11.482.05
16 Feb 2015
11.483.00
17 Feb 2015
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
Remove malware/grayware files that dropped/downloaded TROJ_DOFOIL.UKL. (Note: Please skip this step if the threats listed below have already been removed.)
Step 3
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 4
Scan your computer with your Trend Micro product and note files detected as TROJ_DOFOIL.UKL
Step 5
Restart in Safe Mode
Step 6
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
- {installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
- {installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
- {installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
- {installed program name in the system} = "%Application Data%\{random folder name}\{random file name}.exe"
Step 7
Search and delete these folders
- %Application Data%\{random folder name}
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DOFOIL.UKL. 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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