TROJ_DROPPR.NAC
Windows 2000, Windows XP, Windows Server 2003
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 creates the following folders:
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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 Trojan deletes the following files:
- %User Temp%\nsx1.tmp
(Note: %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Nationalcrf
Description = "Providesung a domain server for NI security."
Dropping Routine
This Trojan drops the following files:
- %User Temp%\HMCU.exe
- %User Temp%\avle.exe
- %System%\yygeym.exe
- \192.168.0.1\admin$\NewArea.exe
- \192.168.0.1\C$\NewArean.exe
- \192.168.0.1\D$\NewArea.exe
- \192.168.0.1\E$\NewArea.exe
- \192.168.0.1\F$\NewArea.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Nationalcrf
- Description = "Providesung a domain server for NI security."
Step 3
Search and delete these components
- %User Temp%\HMCU.exe
- %User Temp%\avle.exe
- %System%\yygeym.exe
- \192.168.0.1\admin$\NewArea.exe
- \192.168.0.1\C$\NewArean.exe
- \192.168.0.1\D$\NewArea.exe
- \192.168.0.1\E$\NewArea.exe
- \192.168.0.1\F$\NewArea.exe
Step 4
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPR.NAC. 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 6
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.
- %User Temp%\nsx1.tmp
Did this description help? Tell us how we did.