WORM_OTORUN.EJ
Trojan Horse (Symantec); Worm:Win32/Rorpian (Microsoft); Net-Worm.Win32.Kolab.xaq (Kaspersky); W32/Kolab (Mcafee)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Propagates via flashdrives
This worm deletes registry entries, causing some applications and programs to not function properly.
It drops copies of itself in all removable drives.
It deletes itself after execution.
TECHNICAL DETAILS
65,544 bytes
EXE
Yes
15 Mar 2011
Drops files
Installation
This worm drops the following copies of itself into the affected system:
- %User Temp%\srv{random characters}.tmp
(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.)
It drops the following non-malicious file:
- %User Temp%\srv{random characters}.ini
(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.)
Autostart Technique
This worm registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\srv{random characters}
Other System Modifications
This worm adds the following registry keys as part of its installation routine:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Safeboot\Minimal\
srv{random characters}
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
netsvcs = srv{random characters}{user-defined list of services}
(Note: The default value data of the said registry entry is {user-defined list of services}.)
It deletes the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters\
Interfaces\{Network ID}
DhcpDefaultGateway = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters\
Interfaces\{Network ID}
DhcpDomain = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters\
Interfaces\{Network ID}
DhcpSubnetMaskOpt = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{Network ID}\Parameters\
Tcpip
DhcpDefaultGateway = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\{Network ID}\Parameters\
Tcpip
DhcpSubnetMaskOpt = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters
DhcpNameServer = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters
DhcpDomain = {user-defined}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters\
Interfaces\{Network ID}
DhcpNameServer = {user-defined}
Propagation
This worm drops copies of itself in all removable drives.
The said .INF file contains the following strings:
{garbage characters}
[aUtorun]
AcTioN=open
{garbage characters}
icON=%winDiR%\SyStEM32\sheLl32.DLl,4
{garbage characters}
USeAutoPlay=1
{garbage characters}
oPeN=RundLL32.Exe sETup50039.FON,2B9828
{garbage characters}
sHell\exPloRE\cOMmaNd=ruNDll32.eXE setUp50039.fOn,2b9828
{garbage characters}
SHELl\oPen\cOMmanD=rUNDll32.EXe SeTup50039.Fon,2B9828
{garbage characters}
Other Details
This worm deletes itself after execution.
NOTES:
It also creates the following .LNK component files in shared folders.
When users double-click these files, its dropped copy is automatically executed:
- autorun.inf
- myporno.avi.lnk
- pornmovs.lnk
- setup{number}.lnk
- setup{numbers}.fon
SOLUTION
8.900
7.903.00
15 Mar 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.EJ using either the Startup Disk or Recovery Console
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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
- srv{random characters}
- srv{random characters}
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Safeboot\Minimal
- srv{random characters}
- srv{random characters}
Step 4
Restore this modified 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\SvcHost
- From: netsvcs = srv{random characters}{user-defined list of services}
To: {user-defined list of services}
- From: netsvcs = srv{random characters}{user-defined list of services}
Step 5
Search and delete this file
Step 6
Search and delete AUTORUN.INF files created by WORM_OTORUN.EJ that contain these strings
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.EJ. 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 8
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.
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