TROJ_DLOADER.NEM
TrojanDownloader:Win32/Roficor.A (Microsoft)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
It connects to certain websites to send and receive information. It terminates itself if it detects it is being run in a virtual environment. However, as of this writing, the said sites are inaccessible.
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.
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\RunOnce
{malware filename} = "{malware path and filename}"
Other System Modifications
This Trojan deletes the following files:
- %Application Data%\Microsoft\Crypto\DES64v7\dtlcntr.exe
- %Application Data%\Microsoft\Crypto\DES64v7\googletoolbar.exe
- %Application Data%\Microsoft\Crypto\DES64v7\active.dll
- %Application Data%\Microsoft\Crypto\DES64v7\detect.dll
(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.)
Download Routine
This Trojan saves the files it downloads using the following names:
- {malware path}\ctfmon.exe
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
Other Details
This Trojan connects to the following website to send and receive information:
- http://{BLOCKED}lace.{BLOCKED}ightparadox.com/major/images/view.php
- http://{BLOCKED}lace.{BLOCKED}ightparadox.com/major/images/read.php
- http://{BLOCKED}ace.{BLOCKED}ightparadox.com/major/txt/read.php
- http://{BLOCKED}machine.{BLOCKED}equake.com/major/images/view.php
- http://{BLOCKED}awchine.{BLOCKED}equake.com/major/images/read.php
- http://{BLOCKED}machine.{BLOCKED}equake.com/major/txt/read.php
expected response from server contains the string DEXT87
It terminates itself if it detects it is being run in a virtual environment.
However, as of this writing, the said sites are inaccessible.
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
Scan your computer with your Trend Micro product and note files detected as TROJ_DLOADER.NEM
Step 3
Restart in Safe Mode
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\RunOnce
- {malware filename} = "{malware path and filename}"
- {malware filename} = "{malware path and filename}"
Step 5
Search and delete these files
- {malware path}\ctfmon.exe
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADER.NEM. 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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