BKDR_NETHIEF.XPE
RDN/BackDoor-TW!c (McAfee); Trojan Horse (Symantec); Fat-Obfuscated (AVG)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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 backdoor 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 backdoor creates the following folders:
- %User Profile%\APPLIC~1\mntat
(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.)
Other System Modifications
This backdoor deletes the following files:
- msexw.zip
Dropping Routine
This backdoor drops the following files:
- %User Startup%\msexw.lnk
- %User Profile%\mntat\msexw.zip
- %User Profile%\mntat\msdis.dll
- %User Profile%\mntat\msexc.exe
(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %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.)
Other Details
This backdoor connects to the following possibly malicious URL:
- http://www.{BLOCKED}e.asia:80/{random path}
- {BLOCKED}6.233.16
This report is generated via an automated analysis system.
SOLUTION
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
Search and delete these components
- %User Startup%\msexw.lnk
- %User Profile%\mntat\msexw.zip
- %User Profile%\mntat\msdis.dll
- %User Profile%\mntat\msexc.exe
Step 3
Search and delete this folder
- %User Profile%\APPLIC~1\mntat
Step 4
Scan your computer with your Trend Micro product to delete files detected as BKDR_NETHIEF.XPE. 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 5
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- msexw.zip
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