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Discovered: May 28, 2003
Updated: May 12, 2010 8:47:47 AM
Type: Trojan
Infection Length: Varies
Systems Affected: Windows

Infostealer.Lemir.Gen is a generic detection for a group of Trojan horse programs that attempt to steal account information from the "Legend of Mir 2" online game and send it to the author of the Trojan.

The Trojan attempts to log details such as video game registration keys and online account information. In order to successfully achieve its primary function, the threat must run on a computer that contains the video game in question and is connected to a network.

This threat can often arrive by the following means:

  • File-sharing networks, as game enhancements
  • Online forum posts

If a Symantec antivirus product displays a detection alert for this threat, it means the computer is already protected and the Symantec product will effectively remove it from the computer.

Antivirus Protection Dates

  • Initial Rapid Release version May 28, 2003
  • Latest Rapid Release version August 03, 2019 revision 007
  • Initial Daily Certified version May 28, 2003 revision 018
  • Latest Daily Certified version August 04, 2019 revision 002
  • Initial Weekly Certified release date May 28, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Technical Description

Infostealer.Lemir.Gen is a generic detection for a group of Trojan horses that attempt to steal account information from the "Legend of Mir 2" online game and send it to the author of the Trojan.

Background information
"Legend of Mir 2" is a Massively Multiplayer Online Role-Playing Game (MMORPG). An MMORPG is a genre of computer games in which a large number of players interact with one another within a virtual game world. The game is set in an ancient oriental world in which, players can assume one of four different roles and fight alongside others to rid the virtual world of evil.

To play the game, a user sets up an account with the publishing company that hosts the game. They can then develop their character over time by carrying out missions and interacting with thousands of other gamers around the world.

Who creates these types of Trojans?
The primary purpose of this type of Trojan is to steal account information for the "Legend of Mir 2" game. This would allow the attacker to play the game without paying for it. However, as the popularity of online video games rose, criminals looking to make money illegally began to take more notice.

While passwords and account information could be sold in the underground economy, a much more enticing market is in-game items. Given the high premium some users were willing to pay for such items, a portion of the underground economy has developed that focus on stealing and then selling such items below the legitimate market price.

How do these threats arrive on a computer?
While there are many different avenues to infection, the more common methods include file-sharing networks and online forum posts.

In the file-sharing realm, hackers often make their threat available under the guise of cracks, enhancements, or mods for a popular game. When a user downloads the files the Trojan is often bundled alongside the intended download. In other cases, the intended download may not be included at all, leaving the user with nothing but a Trojan when the download is run.

These threats can also be obtained through game forums, linked by spammed comments in various discussions. A spammer may offer a solution to a gaming problem requiring a download, or simply add unrelated comments to a thread.

Given the intended goal in either situation, the user generally has the game installed on their computer, and if the threat is run, the information is successfully stolen by the hackers.

What is the goal of this threat?
While in some cases the malware author may use a stolen account to play the game, the original user can often change their password or disable the account once they realize the theft has taken place. Thus, the underlying goal of most threats detected as Infostealer.Lemir.Gen is to obtain in-game items. The accounts gathered by the attackers using such threats are often cleared of in-game items, selling them off to other players in-game, or by putting them up for sale on online auction sites.

What else can the Trojan do?
The Trojan may end processes of certain antivirus and firewall software.

It also has the ability to restart itself, if its own process is ended. This is often done by starting multiple identical processes that monitor the status of each other and restarts new processes if one has ended.

Are there any tell-tale signs?
While the actual actions carried out by these threats generally go unnoticed, the end result does not. A user may one day, upon logging into their game, find that their in-game items are gone. In other cases, they may not be able to log in at all. This could either be because the hacker has changed their password, or their account has been banned by the game administrators.

What are the risks?
The largest risk is the time and money invested in the online game. Users generally find it very difficult to get their in-game items back. Re-establishing a hacked account that has been banned by game administrators can be equally as challenging.

What can I do to minimize the risks?
As a general rule, users should always run up-to-date antivirus software with real-time protection such as Norton Antivirus, Norton Internet Security, Norton 360 or Symantec Endpoint Protection . In addition, a firewall -- or better still, an Intrusion Prevention System (IPS) -- will help to block download activities initiated by these types of malicious programs. Program controls such as those found in Symantec Endpoint Protection can also help to prevent programs such as these from executing in the first place.

How can I find out more?

Advanced users can submit a sample to Threat Expert to obtain a detailed report of the system and file system changes caused by a threat.


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.


You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your computer has been affected by this risk.

Before proceeding further we recommend that you run a full system scan . If that does not resolve the problem you can try one of the options available below.

If you are a Norton product user, we recommend you try the following resources to remove this risk.

Removal Tool

If you have an infected Windows system file, you may need to replace them using from the Windows installation CD .

How to reduce the risk of infection
The following resources provide further information and best practices to help reduce the risk of infection.

If you are a Symantec business product user, we recommend you try the following resources to remove this risk.

Identifying and submitting suspect files
Submitting suspicious files to Symantec allows us to ensure that our protection capabilities keep up with the ever-changing threat landscape. Submitted files are analyzed by Symantec Security Response and, where necessary, updated definitions are immediately distributed through LiveUpdate™ to all Symantec end points. This ensures that other computers nearby are protected from attack. The following resources may help in identifying suspicious files for submission to Symantec.

Removal Tool

If you have an infected Windows system file, you may need to replace them using from the Windows installation CD .

How to reduce the risk of infection
The following resource provides further information and best practices to help reduce the risk of infection.
Protecting your business network

The following instructions pertain to all current Symantec antivirus products.

1. Performing a full system scan
How to run a full system scan using your Symantec product

2. Restoring settings in the registry
Many risks make modifications to the registry, which could impact the functionality or performance of the compromised computer. While many of these modifications can be restored through various Windows components, it may be necessary to edit the registry. See in the Technical Details of this writeup for information about which registry keys were created or modified. Delete registry subkeys and entries created by the risk and return all modified registry entries to their previous values.

Writeup By: Éamonn Young