TROJ_SMALL.LOR
TrojanDownloader:Win32/Small (Microsoft); AdClicker-BA (McAfee); Trojan.Elitebar (Symantec); Trojan-Downloader.Win32.Small.ya (Kaspersky); RiskTool.Win32.ProcessPatcher.Sml!cobra (v) (not malicious) (Sunbelt); Trojan horse Downloader.Small.17.AZ (AVG)
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.
It deletes itself after execution.
TECHNICAL DETAILS
7,168 bytes
EXE
No
13 Apr 2013
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.
Other System Modifications
This Trojan deletes the following files:
- %Temp%\scs1.tmp
- %Temp%\scs2.tmp
- %Temp%\scs3.tmp
- %Temp%\scs4.tmp
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "iexplore.exe"
(Note: The default value data of the said registry entry is iexplore.exe.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = "4117b81"
(Note: The default value data of the said registry entry is 41107b81.)
Dropping Routine
This Trojan drops the following files:
- %System Root%\silent093.exe
- %System Root%\protas.exe
- %User Temp%\ieE8AA.tmp
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://install.{BLOCKED}miracle.com/silent_install.exe
- http://install.{BLOCKED}miracle.com/protector.exe
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
- From: Name = "iexplore.exe"
To: Name = ""iexplore.exe""
- From: Name = "iexplore.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
- From: ID = "4117b81"
To: ID = ""41107b81""
- From: ID = "4117b81"
Step 3
Search and delete these components
- %System Root%\silent093.exe
- %System Root%\protas.exe
- %User Temp%\ieE8AA.tmp
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_SMALL.LOR. 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.
- %Temp%\scs1.tmp
- %Temp%\scs2.tmp
- %Temp%\scs3.tmp
- %Temp%\scs4.tmp
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