TROJ_DELF.JDT
Trojan:Win32/Meredrop (Microsoft); Downloader (Symantec); Trojan.Win32.Meredrop (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
272,384 bytes
EXE
No
12 Sep 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.
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\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}
Other System Modifications
This Trojan deletes the following files:
- %Windows%\addins\~1.tmp
- %Windows%\AppPatch\~2.tmp
- %Windows%\Config\~3.tmp
- %Windows%\Cursors\~4.tmp
- %Windows%\Debug\~5.tmp
- %Windows%\ehome\~6.tmp
- %Windows%\Fonts\~7.tmp
- %Windows%\Help\~8.tmp
- %Windows%\ime\~9.tmp
- %Windows%\inf\~A.tmp
- %Windows%\Installer\~B.tmp
- %Windows%\java\~C.tmp
- %Windows%\Media\~D.tmp
- %Windows%\msagent\~E.tmp
- %Windows%\msapps\~F.tmp
- %Windows%\mui\~10.tmp
- %Windows%\pchealth\~11.tmp
- %Windows%\PeerNet\~12.tmp
- %Windows%\Prefetch\~13.tmp
- %Windows%\pss\~14.tmp
- %Windows%\repair\~15.tmp
- %Windows%\Resources\~16.tmp
- %Windows%\security\~17.tmp
- %Windows%\srchasst\~18.tmp
- %Windows%\Tasks\~19.tmp
- %Windows%\twain_32\~1A.tmp
- %Windows%\Web\~1B.tmp
- %Windows%\WinSxS\~1C.tmp
- %Windows%\addins\~1E.tmp
- %Windows%\AppPatch\~1F.tmp
- %Windows%\Config\~20.tmp
- %Windows%\Cursors\~21.tmp
- %Windows%\Debug\~22.tmp
- %Windows%\ehome\~23.tmp
- %Windows%\Fonts\~24.tmp
- %Windows%\Help\~25.tmp
- %Windows%\ime\~26.tmp
- %Windows%\inf\~27.tmp
- %Windows%\Installer\~28.tmp
- %Windows%\java\~29.tmp
- %Windows%\Media\~2A.tmp
- %Windows%\msagent\~2B.tmp
- %Windows%\msapps\~2C.tmp
- %Windows%\mui\~2D.tmp
- %Windows%\pchealth\~2E.tmp
- %Windows%\PeerNet\~2F.tmp
- %Windows%\Prefetch\~30.tmp
- %Windows%\pss\~31.tmp
- %Windows%\repair\~32.tmp
- %Windows%\Resources\~33.tmp
- %Windows%\security\~34.tmp
- %Windows%\srchasst\~35.tmp
- %Windows%\Tasks\~36.tmp
- %Windows%\twain_32\~37.tmp
- %Windows%\Web\~38.tmp
- %Windows%\WinSxS\~39.tmp
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
It adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}
HKEY_CLASSES_ROOT\CLSID\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}\
InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Ext\CLSID
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}
NoExplorer = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Ext\CLSID
{79B7C870-3FA2-4410-A297-9AC5D1A407D2} = "1"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\strFileDestVar1.cpl
- %User Temp%\~1Dfiles
- %Windows%\PeerNet\upnp.dll
- %Windows%\PeerNet\mqoa.dll
- %User Temp%\3A.tmp
- %Windows%\msapps\sens.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.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
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\CLSID
- {79B7C870-3FA2-4410-A297-9AC5D1A407D2}
- In HKEY_CLASSES_ROOT\CLSID\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Ext
- CLSID
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\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{79B7C870-3FA2-4410-A297-9AC5D1A407D2}
- NoExplorer = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Ext\CLSID
- {79B7C870-3FA2-4410-A297-9AC5D1A407D2} = "1"
Step 5
Search and delete these files
- %User Temp%\strFileDestVar1.cpl
- %User Temp%\~1Dfiles
- %Windows%\PeerNet\upnp.dll
- %Windows%\PeerNet\mqoa.dll
- %User Temp%\3A.tmp
- %Windows%\msapps\sens.dll
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_DELF.JDT. 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.
- %Windows%\addins\~1.tmp
- %Windows%\AppPatch\~2.tmp
- %Windows%\Config\~3.tmp
- %Windows%\Cursors\~4.tmp
- %Windows%\Debug\~5.tmp
- %Windows%\ehome\~6.tmp
- %Windows%\Fonts\~7.tmp
- %Windows%\Help\~8.tmp
- %Windows%\ime\~9.tmp
- %Windows%\inf\~A.tmp
- %Windows%\Installer\~B.tmp
- %Windows%\java\~C.tmp
- %Windows%\Media\~D.tmp
- %Windows%\msagent\~E.tmp
- %Windows%\msapps\~F.tmp
- %Windows%\mui\~10.tmp
- %Windows%\pchealth\~11.tmp
- %Windows%\PeerNet\~12.tmp
- %Windows%\Prefetch\~13.tmp
- %Windows%\pss\~14.tmp
- %Windows%\repair\~15.tmp
- %Windows%\Resources\~16.tmp
- %Windows%\security\~17.tmp
- %Windows%\srchasst\~18.tmp
- %Windows%\Tasks\~19.tmp
- %Windows%\twain_32\~1A.tmp
- %Windows%\Web\~1B.tmp
- %Windows%\WinSxS\~1C.tmp
- %Windows%\addins\~1E.tmp
- %Windows%\AppPatch\~1F.tmp
- %Windows%\Config\~20.tmp
- %Windows%\Cursors\~21.tmp
- %Windows%\Debug\~22.tmp
- %Windows%\ehome\~23.tmp
- %Windows%\Fonts\~24.tmp
- %Windows%\Help\~25.tmp
- %Windows%\ime\~26.tmp
- %Windows%\inf\~27.tmp
- %Windows%\Installer\~28.tmp
- %Windows%\java\~29.tmp
- %Windows%\Media\~2A.tmp
- %Windows%\msagent\~2B.tmp
- %Windows%\msapps\~2C.tmp
- %Windows%\mui\~2D.tmp
- %Windows%\pchealth\~2E.tmp
- %Windows%\PeerNet\~2F.tmp
- %Windows%\Prefetch\~30.tmp
- %Windows%\pss\~31.tmp
- %Windows%\repair\~32.tmp
- %Windows%\Resources\~33.tmp
- %Windows%\security\~34.tmp
- %Windows%\srchasst\~35.tmp
- %Windows%\Tasks\~36.tmp
- %Windows%\twain_32\~37.tmp
- %Windows%\Web\~38.tmp
- %Windows%\WinSxS\~39.tmp
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