TROJ_DLOADR.AR
Adware:Win32/IEHlpr (Microsoft); [0000cca0.EXE]:Allsum.dll (McAfee); Trojan.Yigather (Symantec); Adware.IEHelper (fs) (Sunbelt); Adware:W32/Iehlpr (FSecure)
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
176,128 bytes
EXE
No
14 May 2012
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:
- %User Profile%\Microsoft\IEHelper
(Note: %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.)
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\{16B770A0-0E87-4278-B748-2460D64A8386}
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CLASSES_ROOT\IEHelper.MyIEHelper.1
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHelper.MyIEHelper.1\CLSID
HKEY_CLASSES_ROOT\IEHelper.MyIEHelper
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHelper.MyIEHelper\CLSID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
IEHelper.MyIEHelper\CurVer
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\ProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\VersionIndependentProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\Programmable
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\TypeLib
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0\
FLAGS
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0\
0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0\
0\win32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0\
HELPDIR
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}\ProxyStubClsid
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}\ProxyStubClsid32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}\TypeLib
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}\TypeLib
Version = "1.0"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\_checktemptest
- %User Profile%\IEHelper\IEHelper_5052.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.. %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.)
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
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
- IEHelper.MyIEHelper.1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IEHelper.MyIEHelper.1
- CLSID
- In HKEY_CLASSES_ROOT
- IEHelper.MyIEHelper
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IEHelper.MyIEHelper
- CLSID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\IEHelper.MyIEHelper
- CurVer
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {16B770A0-0E87-4278-B748-2460D64A8386}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
- ProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
- VersionIndependentProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
- Programmable
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}
- TypeLib
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
- Browser Helper Objects
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
- {2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}
- 1.0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0
- FLAGS
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0
- 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0\0
- win32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{2511DE40-34A3-4C6A-B1B2-C5C92A2F00BE}\1.0
- HELPDIR
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}
- ProxyStubClsid
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}
- ProxyStubClsid32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}
- TypeLib
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\Classes\CLSID\{16B770A0-0E87-4278-B748-2460D64A8386}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{A4BC2506-C00C-4D2E-B47F-0BB4C2C74CCF}\TypeLib
- Version = "1.0"
Step 5
Search and delete these files
- %User Temp%\_checktemptest
- %User Profile%\IEHelper\IEHelper_5052.dll
Step 6
Search and delete this folder
- %User Profile%\Microsoft\IEHelper
Step 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADR.AR. 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.
Did this description help? Tell us how we did.