Alert level

Worm:Win32/Taterf.B


Encyclopedia entry
Updated: Feb 12, 2009  |  Published: Feb 06, 2009

Aliases
  • Win32/Frethog.CUM (CA)
  • W32/Lineage.KHE (Panda)
  • Mal/Frethog-B (Sophos)
  • Trojan-GameThief.Win32.Magania.ammv (Kaspersky)
  • Generic PWS.ak (McAfee)
  • Infostealer.Gampass (Symantec)

Alert Level (?)
Severe

Antimalware protection details
Microsoft recommends that you download the latest definitions to get protected.
Detection last updated:
Definition: 1.69.995.0
Released: Nov 16, 2009
Detection initially created:
Definition: 1.49.2195.0
Released: Jan 19, 2009


Summary

Worm:Win32/Taterf.B is a worm that spreads via logical drives to steal login and account details for popular online games.


Symptoms

System Changes
The following system changes may indicate the presence of this malware:
  • The presence of the following files:
    <system folder>\kamsoft.exe
    <system folder>\gasretyw<number>.dll
  • The presence of the following registry modifications:
    Added value: "kamsoft"
    With data: "<system folder>\kamsoft.exe"
    To subkey: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run


Technical Information (Analysis)

Worm:Win32/Taterf.B is a worm that spreads via logical drives to steal login and account details for popular online games.
Installation
Worm:Win32/Taterf.B is composed of a loader component and a payload component. It drops the following files in the system with the attributed "hidden", "system", and "read-only":
  • <system folder>\kamsoft.exe - copy of itself, loader component
  • <system folder>\gasretyw<number>.dll - payload component; detected as Worm:Win32/Taterf.B.dll
 
where <number> is a number between 0 to 9.
 
Note - <system folder> refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the System folder for Windows 2000 and NT is C:\Winnt\System32; and for XP and Vista is C:\Windows\System32.
 
Both of these files are detected as Worm:Win32/Taterf.B.
 
It modifies the system registry so that its dropped copy runs every time Windows starts:
 
Adds value: "kamsoft"
With data: "<system folder>\kamsoft.exe"
To subkey: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
 
It then injects its payload component into the currently-running "explorer.exe" process.
Spreads Via...
Logical Drives
Win32/Taterf.B attempts to drop the following files in the root of all drives from C: to Z::
  • m9ma.exe - copy of itself
  • autorun.inf - INF file that enables the worm copy to run automatically when the drive is accessed and Autorun is enabled
 
To ensure that Autorun is enabled, it may modify the following registry entry:
 
Adds value: "NoDriveTypeAutoRun"
With data: "00000091"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
Payload
Disables Antivirus Services
Worm:Win32/Taterf.B attempts to stop the real-time protection service of antivirus products from the following vendors:
  • Kaspersky
  • Rising
 
Modifies System Settings
To avoid detection, Win32/Taterf.B changes the way that the system handles hidden files and folders by adding the following registry entries:s:
 
Adds value: "CheckedValue"
With data: "0"
To key: HKLM\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
 
Adds value: "Hidden"
With data: "2"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
 
Adds value: "ShowSuperHidden"
With data: "0"
To subkey: HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
 
Steals User Details
Win32/Taterf.B steals online game accounts and passwords by monitoring the system, especially the following game processes:
  • pol.exe
  • ageofconan.exe
  • coc.exe
  • knightonline.exe
  • lotroclient.exe
  • turbinelauncher.exe
 
Analysis by Shawn Wang


Prevention

Take the following steps to help prevent infection on your system:
  • Enable a firewall on your computer.
  • Get the latest computer updates for all your installed software.
  • Use up-to-date antivirus software.
  • Use caution when opening attachments and accepting file transfers.
  • Use caution when clicking on links to web pages.
  • Avoid downloading pirated software.
  • Protect yourself against social engineering attacks.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
To turn on the Windows Firewall in Windows Vista
  1. Click Start, and click Control Panel.
  2. Click Security.
  3. Click Turn Windows Firewall on or off.
  4. Select On.
  5. Click OK.
To turn on the Internet Connection Firewall in Windows XP
  1. Click Start, and click Control Panel.
  2. Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
  3. Click Change Windows Firewall Settings.
  4. Select On.
  5. Click OK.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.
 
You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
To turn on Automatic Updates in Windows Vista
  1. Click Start, and click Control Panel
  2. Click System and Maintainance.
  3. Click Windows Updates.
  4. Select a setting. Microsoft recommends selecting Install updates automatically and choose a time that is convenient for you. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
To turn on Automatic Updates in Windows XP
  1. Click Start, and click Control Panel
  2. Click System.
  3. Click Automatic Updates.
  4. Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software that is updated with the latest signature files. Antivirus software is available from several sources. For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.
Use caution when opening attachments and accepting file transfers
Exercise caution with e-mail and attachments received from unknown sources, or received unexpectedly from known sources.  Use extreme caution when accepting file transfers from known or unknown sources.
Use caution when clicking on links to web pages
Exercise caution with links to web pages that you receive from unknown sources, especially if the links are to a web page that you are not familiar with or are suspicious of. Malicious software may be installed in your system simply by visiting a web page with harmful content.
Avoid downloading pirated software
Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information. please see our article 'The risks of obtaining and using pirated software'.
Protect yourself from social engineering attacks
While attackers may attempt to exploit vulnerabilities in hardware or software in order to compromise a system, they also attempt to exploit vulnerabilities in human behavior in order to do the same. When an attacker attempts to take advantage of human behavior in order to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted system. For more information, please see our article 'What is social engineering?'.


Recovery

Manual removal is not recommended for this threat. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as the Microsoft online scanner (http://safety.live.com). For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.
 
This threat may make lasting changes to an affected system’s configuration that will NOT be restored by detecting and removing this threat. For more information on returning an affected system to its pre-infected state, please see the following article/s: