WORM_OTORUN.LJL
Trojan:Win32/Rimecud.A (Microsoft); Mal/Zbot-ASK (Sophos)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives by connecting affected removable drives to a system. It arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
87,552 bytes
EXE
Yes
28 Oct 2011
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It arrives via removable drives.
It 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 worm drops the following copies of itself into the affected system:
- %User Profile%\xvlof.exe
(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 worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%User Profile%\xvlof.exe"
Propagation
This worm creates the following folders in all removable drives:
- {drive}:\luckasta
It drops the following copy(ies) of itself in all removable drives:
- {drive}:\luckasta\tamanten.exe
It 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]
USEAUTOPLAY=1
shellexcute=luckasta//tamanten.exe
icon=luckasta//tamanten.exe
Shell\going\home
{random characters}
open=luckasta//tamanten.exe
shell\\\Open\\\command=luckasta//tamanten.exe
shell\\\Explore\\\command=luckasta//tamanten.exe
action=Open folder to view files usingaWindowaExplorer
Dropping Routine
This worm sets the attributes of its dropped file(s) to the following:
- Hidden
- System
- Read Only
SOLUTION
9.200
8.528.02
28 Oct 2011
8.529.00
29 Oct 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
Identify and delete files detected as WORM_OTORUN.LJL using the Recovery Console
Step 3
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 NT\CurrentVersion\Winlogon
- Taskman = %User Profile%\xvlof.exe
- Taskman = %User Profile%\xvlof.exe
Step 4
Search and delete this folder
Step 5
Search and delete AUTORUN.INF files created by WORM_OTORUN.LJL that contain these strings
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.LJL. 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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