QDDOS

QDDOS is a family of multi-component malware known to launch denial of service (DoS) attacks on specific websites if certain conditions are met. One of its variants detected in 2011 was implicated in a DoS attack launched against a variety of Korean websites in 2011.

Before executing the DoS attack, QDDOS obtains system information such as user name of logged-in users and computer name from targets. Obtained information is then communicated back to its servers.

QDDOS malware are also capable of deleting files that use certain extensions, overwriting the Master Boot Record (MBR), modifying HOSTS files, and preventing users from accessing certain websites.

Installation

This Trojan drops the following files:

• %System%\faultrep.dat
• %System%\tlntwye.dat
• %System%\tljoqgv.dat
• %System%\noise03.dat
• %System%\rtdrvupr.exe
• %System%\m{3 random alphabetic characters}svc.dll
• %System%\w{2 random alphabetic characters}csvc.dll
• %System%\s{3 random alphabetic characters}svc.dll
• %System%\nt{2 random alphabetic characters}{2 random numeric characters}.dll
• %Windows%\KB24919.log

(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.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
m{3 random alphabetic characters}svc = "m{3 random alphabetic characters}svc"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
w{2 random alphabetic characters}csvc = "w{2 random alphabetic characters}csvc"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
s{3 random alphabetic characters}svc = "s{3 random alphabetic characters}svc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
Type = "20"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
ImagePath = "%System Root%\system32\svchost.exe -k m{3 random alphabetic characters}svc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
DisplayName = "Microsoft DNS resolve Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc
Description = "Provides DNS resolve.If this service is stopped, system cannot be well performed"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc\Parameters
ServiceDll = = "%System Root%\system32\m{3 random alphabetic characters}svc.dll"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
Type = "20"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
ImagePath = "%System Root%\system32\svchost.exe -k s{3 random alphabetic characters}svc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
DisplayName = "Removal stoarage Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc
Description = "Allows Removal storage. If this service is stopped, system cannot be well performed"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc\Parameters
ServiceDll = "%System Root%\system32\s{3 random alphabetic characters}svc.dll"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
Type = "20"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
ImagePath = = "%System Root%\system32\svchost.exe -k w{2 random alphabetic characters}csvc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
DisplayName = "Windows DNS Security controler Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc
Description = "Transmits DNS Security controler.If this service is stopped, system cannot be well performed"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc\Parameters
ServiceDll = "%System Root%\system32\w{2 random alphabetic characters}csvc.dll"

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\m{3 random alphabetic characters}svc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\s{3 random alphabetic characters}svc

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\w{2 random alphabetic characters}csvc

Other Details

This Trojan connects to the following possibly malicious URL:

• {BLOCKED}.{BLOCKED}.11.82
• {BLOCKED}.{BLOCKED}.253.166