Malware type: Worm

Aliases: No Alias Found

In the wild: Yes

Destructive: No

Language: English

Platform: Windows 98, ME, NT, 2000, XP, Server 2003

Encrypted: No

Overall risk rating:

Reported infections:

Damage potential:


Distribution potential:


Infection Channel 1 : Propagates via removable drives

Infection Channel 2 : Copies itself in all available physical drives


A worm is a malware that is designed to propagate and spread across networks. Worms are known to propagate using one or several of different transmission vectors like email, IRC, network shares, instant messengers (IM), and peer-to-peer (P2P) networks.

Worms do not infect files, but may carry one or more payloads, such as computer security compromise and information theft.

Worms typically modify system settings to automatically start. Users may need to terminate worms before they can be deleted. Also, restoring affected systems may require procedures other than scanning with an antivirus program.

For additional information about this threat, see:

Description created: May. 28, 2009 3:06:35 PM GMT -0800


File type: PE

Memory resident:  Yes

Size of malware: 105,520 Bytes

Initial samples received on: May 17, 2009


Payload 1: Drops files


Arrival, Installation, and Autostart Technique

This worm may be downloaded from remote site(s) by other malware. It may be downloaded unknowingly by a user when visiting malicious Web site(s). It arrives via removable drives.

It drops the following copy(ies) of itself:

  • %System%\xvassdf.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It sets the attributes of its dropped file(s) to the following:

  • Hidden
  • Read-Only
  • System

It injects threads into the following normal process(es):

  • Explorer.exe

It creates the following registry entry(ies) to enable its automatic execution at every system startup:

54dfsger = "%System%\xvassdf.exe"

Propagation via Physical/Removable/Floppy Drives

This worm drops the following copy of itself in all physical and removable drives:

  • d.cmd

It drops an AUTORUN.INF file to automatically execute dropped copies when the drives are accessed.

The AUTORUN.INF file contains the following strings:


Dropping Routine

This worm drops the following component file(s):

As a result, routines of the dropped spyware are also exhibited on the affected system.

Analysis By: Karl Dominguez

Revision History:

First pattern file version: 6.432.02
First pattern file release date: Sep 10, 2009


Minimum scan engine version needed: 8.700

Pattern file needed: 6.443.00

Pattern release date: Sep 14, 2009

Important note: The "Minimum scan engine" refers to the earliest Trend Micro scan engine version guaranteed to detect this threat. However, Trend Micro strongly recommends that you update to the latest version in order to get comprehensive protection. Download the latest scan engine here.


For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

 Step 1: Remove malware files dropped/downloaded by WORM_ONLINEG.KXL  

 Step 2: Restart in Safe Mode  [learn how]

 Step 3:  Delete this registry value  [learn how]

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_CURRENT_USER\Software\Microsoft\
    • 54dfsger = "%System%\xvassdf.exe"

 Step 4: Search and delete AUTORUN.INF files created by WORM_ONLINEG.KXL that contain these strings  [learn how]


 Step 5: Scan your computer with your Trend Micro product to delete files detected as WORM_ONLINEG.KXL  

*Note: 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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