Analysis by: Michael Cabel
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This worm drops copies of itself in all 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.

  TECHNICAL DETAILS

File Size: 28,160 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 26 Feb 2009

Installation

This worm drops the following copies of itself into the affected system:

  • %System Root%\RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

  • %System Root%\RESTORE\k-1-3542-4232123213-7676767-8888886

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It is injected into the following processes running in memory:

  • explorer.exe

Other System Modifications

This worm adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{67KLN5J0-4OPM-00WE-AAX5-77EF1D187563}
StubPath = %System Root%\RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe

Propagation

This worm drops copies of itself in all 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.

The said .INF file contains the following strings:

[AutoRun]
open=RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe

icon=%SystemRoot%\system32\SHELL32.dll,4

action=Open folder to view files

shell\open=Open

shell\open\command=RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe

shell\open\default=1

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 05.868.03
VSAPI PATTERN Date: 26 Feb 2009
VSAPI PATTERN Date: 2/26/2009 12:00:00 AM

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

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry value

[ Learn More ]

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\Active Setup\Installed Components\{67KLN5J0-4OPM-00WE-AAX5-77EF1D187563}
    • StubPath = %System Root%\RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe

Step 4

Search and delete AUTORUN.INF files created by WORM_OTORUN.HZR that contain these strings

[ Learn More ]
[AutoRun]
open=RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RESTORE\k-1-3542-4232123213-7676767-8888886\SysBsm.exe
shell\open\default=1

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result. %System Root%\RESTORE\k-1-3542-4232123213-7676767-8888886

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.HZR. 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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