Win32/Lolyda is a family of trojans that send account information from popular online games to a remote server. They may also download and execute arbitrary files.
Installation
Recent variants of PWS:Win32/Lolyda install by copying themselves to <system folder>\HBmhly.exe and then deleting the originating executable. They also install a file to <system folder>\drivers\HBKernel.sys as a kernel driver service named “HBKernel”. This contains the payload of the malware. If the installer file is unable to communicate with the driver, it instead executes the malware’s payload itself and creates the following registry entry:
To key: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Adds value: HBmhly
With data: “<system folder>\HBmhly.exe –r”
This ensures that it will attempt to recreate the kernel driver service upon system startup.
Earlier variants of PWS:Win32/Lolyda typically install themselves by dropping a file to %temp%\lyloader.exe and then executing this file.
Win32/Lolyda initially deletes the original installer file, then drops two DLLs, placing copies of both of these in both the %temp% and System directories.
Examples of filenames being used in the wild for these DLLs have included:
• D3D9_32.DLL and D3D9_64.DLL
• LYMANGR.DLL and MSDEG32.DLL
• shqmangr.dll and shq.dll
It also drops two further configuration files to %windir%\dxtmechk and <system folder>\REGKEY.hiv, and copies itself to C:\Privilege.dat and <system folder>\DXDLG.exe.
It uses information in <system folder>\REGKEY.hiv to create new registry entries. One variant was observed to create the following
To key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
Adds value: DXDLG32
With data: DXDLG.exe
Adds value: MSDCG32
With data: LyLeador.exe
Adds value: MSDHG32
With data: LyLoadhr.exe
Adds value: MSDMG32
With data: LyLoadmr.exe
Adds value: MSDOG32
With data: LyLoador.exe
Adds value: MSDQG32
With data: LyLoadqr.exe
Adds value: MSDSG32
With data: LyLoadar.exe
Adds value: MSDWG32
With data: LyLoadbr.exe
These modifications are an attempt to ensure that programs with these names run upon system startup.
It then injects code to call the dropped DLLs into services.exe and explorer.exe.
Payload
Downloads and Executes Arbitrary Files
When run, the malware makes a UDP connection to a remote server, from which it may download additional files. These files are saved to disk and then executed.
Servers observed to have been used in the wild include the following:
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61.191.56.153
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222.169.224.183
Steals Online Game Information
Win32/Lolyda examines the window titles of other running processes searching for titles and executables used by popular online role playing games. If any are found, the trojan injects code into these processes to attempt to obtain password and other account information from these games.
Several variants were observed to target the file 'my.exe' from the Chinese game 'Fantasy Westward Journey'.
An earlier variant was observed to target many other files or windows, including the following:
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Pirate King Online (targeted by window title)
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elementclient.exe (Perfect World)
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cq.exe (Spring and Autumn – CQ online)
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gameclient.exe (CGA)
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Conquer.exe (Conquer)
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gc.exe (GhostWar)
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metin2.bin (Metin 2)
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HYO.exe (HY Online)
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china_login.mpr and Login.dll (PCIK)
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WndMgr.dll, WndSys.dll, ThingClassFactory.dll and thing.dll (HX Online)
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Engine.dll, HyNetHandle.dll, XInterface.dll, Core.dll, HYGUI.dll (Lineage II)
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mssdsp.flt
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dump.dll
It also targeted a number of other files by determining whether their MD5 hash values appear on a specified list.
This information is posted to a server. Examples of servers observed to be used in the wild have included:
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6161q1.cn
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6161q2.cn
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6161h1.cn
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6161h2.cn
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zkd520.cn
Analysis by David Wood
Take the following steps to help prevent infection on your computer:
- Enable a firewall on your computer.
- Get the latest computer updates for all your installed software.
- Use up-to-date antivirus software.
- Limit user privileges on the computer.
- Use caution when opening attachments and accepting file transfers.
- Use caution when clicking on links to webpages.
- Avoid downloading pirated software.
- Protect yourself against social engineering attacks.
- Use strong passwords.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
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.
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, such as Microsoft Security Essentials, that is updated with the latest signature files. For more information, see http://www.microsoft.com/windows/antivirus-partners/.
Limit user privileges on the computer
Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.
You can configure UAC in your computer to meet your preferences:
Use caution when opening attachments and accepting file transfers
Exercise caution with email 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 webpages
Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage 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, see '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 to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior 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 computer. For more information, see 'What is social engineering?'.
Use strong passwords
Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see http://www.microsoft.com/protect/yourself/password/create.mspx.
