TROJ_DLOADER.KT
:Generic.bfr!cf, [17.nsis]:Generic.dx!wmm (McAfee); Trojan.Gen.2 (Symantec); ARC:NSIS (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
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
641,717 bytes
EXE
No
06 Oct 2011
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\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsa2.tmp
(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:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsk1.tmp
- %User Temp%\nsa2.tmp
- %User Temp%\instpage.ini
(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.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsa2.tmp\KillProcDLL.dll
- %User Temp%\nsa2.tmp\DLLWaitForKillProgram.dll
- %User Temp%\nsa2.tmp\stack.dll
- %User Temp%\nsa2.tmp\ISCHECK2.dll
- %User Temp%\instpage.ini
- %User Temp%\nsa2.tmp\ioSpecial.ini
- %User Temp%\nsa2.tmp\modern-wizard.bmp
- %User Temp%\nsa2.tmp\InstallOptions.dll
(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.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://upchk.{BLOCKED}k.co.kr/installinfo/{BLOCKED}k/{BLOCKED}k_instchk2.php
This report is generated via an automated analysis system.
SOLUTION
9.200
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsa2.tmp
Step 3
Search and delete these files
- %User Temp%\nsa2.tmp\KillProcDLL.dll
- %User Temp%\nsa2.tmp\DLLWaitForKillProgram.dll
- %User Temp%\nsa2.tmp\stack.dll
- %User Temp%\nsa2.tmp\ISCHECK2.dll
- %User Temp%\instpage.ini
- %User Temp%\nsa2.tmp\ioSpecial.ini
- %User Temp%\nsa2.tmp\modern-wizard.bmp
- %User Temp%\nsa2.tmp\InstallOptions.dll
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADER.KT. 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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