BKDR_DARKMOON.CS

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes the initially executed copy of itself.

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This backdoor drops the following copies of itself into the affected system:

• %System%\mstankss.exe (if not logged in as an administrator)
• %System%:mstankss.exe (if logged in as an administrator)

(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 injects itself into the following processes running in the affected system's memory:

• explorer.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• KGGJ^&#SF

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{7CD14E9C-B986-F4B1-9157-FDF1F7ABC18D}
StubPath = "%System%:mstankss.exe" or "%System%\mstankss.exe"

Other System Modifications

This backdoor adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{7CD14E9C-B986-F4B1-9157-FDF1F7ABC18D}

Other Details

This backdoor deletes the initially executed copy of itself

NOTES:

Backdoor Routine

This backdoor starts a hidden default browser.

It injects codes in the hidden default browser to perform its backdoor routines.

It connects to email-dns.{BLOCKED}s-blog.com at port 80 to receive binary instructions. It then executes the binary instructions.