TROJ_DROPPR.VY
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
811,871 bytes
EXE
No
22 Nov 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.
Autostart Technique
This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\explorer\
Browser Helper Objects\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
Other System Modifications
This Trojan deletes the following files:
- %Temp%\scs4.tmp
- %Temp%\scs7.tmp
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)
It adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
HKEY_CLASSES_ROOT\CLSID\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}\
InprocServer32
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
ConsentPromptBehaviorAdmin = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
NoExplorer = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
EXT\CLSID
{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA} = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main\FeatureControl\
FEATURE_ENABLE_SCRIPT_PASTE_URLACTION_IF_PROMPT
iexplore.exe = "1"
Dropping Routine
This Trojan drops the following files:
- %User Startup%\inc.exe
- %User Profile%\Application Data\leto.dll
(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 Trojan connects to the following possibly malicious URL:
- http://www.{BLOCKED}ma.it/includes/js/dtree/zika.exe
- http://www.{BLOCKED}stronomy.org/moonwalkers/media/system/js/brtF.dll
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
Close all opened browser windows
Step 3
Delete this registry key
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_CLASSES_ROOT\CLSID
- {0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
- In HKEY_CLASSES_ROOT\CLSID\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
- InprocServer32
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLUA = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- ConsentPromptBehaviorAdmin = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{0EDEF382-D7CF-4721-AD5F-C02DEF981FEA}
- NoExplorer = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\EXT\CLSID
- {0EDEF382-D7CF-4721-AD5F-C02DEF981FEA} = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_ENABLE_SCRIPT_PASTE_URLACTION_IF_PROMPT
- iexplore.exe = "1"
Step 5
Search and delete these components
- %User Startup%\inc.exe
- %User Profile%\Application Data\leto.dll
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPR.VY. 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 7
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%\scs4.tmp
- %Temp%\scs7.tmp
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