Trojan.W97M.MALDROP.AB
TrojanDownloader:O97M/Obfuse.NI!MTB (Microsoft); RDN/Generic Downloader.x (McAfee); Trojan:W97M/Nastjencro.A (FSecure)
Windows
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.
TECHNICAL DETAILS
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.
Installation
This Trojan drops the following copies of itself into the affected system:
- {malware path and file name}.doc
It adds the following processes:
- "%System%\WScript.exe" "%Windows%\Temp\xnxcdiejmj.js"
- "%All Users Profile%\10379.exe"
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )
It creates the following folders:
- %User Profile%\Application Data\Microsoft\Forms
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other System Modifications
This Trojan modifies the following file(s):
- %Application Data%\Microsoft\Office\Word12.pip
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
FileExts\.js\OpenWithProgids\
JSFile
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
FileExts\.js\OpenWithList
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Wow6432Node\Interface\{BEF6E003-A874-101A-8BBA-00AA00300CAB}
(Default) = ""
Dropping Routine
This Trojan drops the following files:
- %All Users Profile%\10379.exe
- %Windows%\Temp\xnxcdiejmj.js
- %Application Data%\Microsoft\UProof\CUSTOM.DIC
- %Application Data%\Microsoft\Office\Word12.pip
- %User Profile%\Application Data\Microsoft\Forms\WINWORD.box
- %Application Data%\Microsoft\Office\VB12.pip
(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). . %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}r.com/Melar.php
- http://docs.{BLOCKED}oft.com
- http://www.{BLOCKED}icro.com
- http://{BLOCKED}uism.com
- {BLOCKED}.192.26
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 2
Identify and terminate files detected as Trojan.W97M.MALDROP.AB
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.js\OpenWithProgids
- JSFile
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.js
- OpenWithList
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_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\Interface\{BEF6E003-A874-101A-8BBA-00AA00300CAB}
- (Default) = ""
Step 5
Search and delete these components
- %All Users Profile%\10379.exe
- %Windows%\Temp\xnxcdiejmj.js
- %Application Data%\Microsoft\UProof\CUSTOM.DIC
- %Application Data%\Microsoft\Office\Word12.pip
- %User Profile%\Application Data\Microsoft\Forms\WINWORD.box
- %Application Data%\Microsoft\Office\VB12.pip
Step 6
Search and delete this folder
- %User Profile%\Application Data\Microsoft\Forms
Step 7
Scan your computer with your Trend Micro product to delete files detected as Trojan.W97M.MALDROP.AB. 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 the following Trend Micro Support pages 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%\Microsoft\Office\Word12.pip
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