WORM_DROPPER.TPD
Windows 2000, Windows XP, Windows Server 2003

Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This worm arrives via removable drives.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
TECHNICAL DETAILS
580,833 bytes
EXE
Yes
23 Dec 2011
Arrival Details
This worm arrives via removable drives.
Installation
This worm drops the following files:
- %Windows%\encoder.txt
- %Windows%\lock.rar
- %Windows%\mouse.exe
- %Windows%\run.vbs
- %Windows%\unlock.exe
- %Windows%\wscntfy32.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
It drops the following copies of itself into the affected system:
- %Windows%\my_facebook_photo.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
Autostart Technique
This worm modifies the following entry(ies) to allow itself to run on safe mode:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,%Windows%\wscntfy32.exe,%Windows%\help\svchost.exe"
(Note: The default value data of the said registry entry is %System%\userinit.exe,.)
Propagation
This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[AutoRun]
open=facebook_photo.exe
shellexecute=facebook_photo.exe
shell\Auto\command=facebook_photo.exe
Dropping Routine
This worm executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}s.3322.org/encoder.txt?67678
SOLUTION
9.200
8.662.08
24 Dec 2011
8.663.00
24 Dec 2011
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
Scan your computer with your Trend Micro product and note files detected as WORM_DROPPER.TPD
Step 3
Identify and delete files detected as WORM_DROPPER.TPD using either the Startup Disk or Recovery Console
Step 4
Restore this modified registry value
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\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe,%Windows%\wscntfy32.exe,%Windows%\help\svchost.exe"
To: Userinit = "%System%\userinit.exe,"
- From: Userinit = "%System%\userinit.exe,%Windows%\wscntfy32.exe,%Windows%\help\svchost.exe"
Step 5
Search and delete these files
- %Windows%\encoder.txt
- %Windows%\lock.rar
- %Windows%\mouse.exe
- %Windows%\run.vbs
- %Windows%\unlock.exe
- %Windows%\wscntfy32.exe
Step 6
Search and delete AUTORUN.INF files created by WORM_DROPPER.TPD that contain these strings
[AutoRun]
open=facebook_photo.exe
shellexecute=facebook_photo.exe
shell\Auto\command=facebook_photo.exe
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_DROPPER.TPD. 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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