BKDR_DASERF.AO

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 does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.

It does not have any downloading capability.

It steals certain information from the system and/or the user.

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 file(s)/component(s):

• %System Root%\Program Files\Common Files\System\Library\msid.dat - If administrator
• %User Profile%\System\Library\msid.dat - If non-administrator

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It drops the following copies of itself into the affected system:

• %System Root%\Program Files\Common Files\System\Library\msnsd.exe - If administrator
• %User Profile%\System\Library\msnsd.exe - If non-administrator

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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

• msmsnsrv

It injects itself into the following processes as part of its memory residency routine:

• explorer.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv
Type = "10" (If administrator only)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv
Start = "2" (If administrator only)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv
ErrorControl = "1" (If administrator only)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv
ImagePath = "%System Drive%\Program Files\Common Files\System\Library\msnsd.exe" (If administrator only)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\msmsnsrv
DisplayName = "Microsoft Windows Network Provider Sevice" (If administrator only)

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

• Terminates Processes
• Delete Files
• Send Files
• Execute Files
• Perform Remote Shell
• Install Services
• Start Services
• Delete Services

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• http://account.{BLOCKED}me.com/jp/
• http://tech.{BLOCKED}et.com/jp/

However, as of this writing, the said sites are inaccessible.

Download Routine

This backdoor connects to the following URL(s) to download its component file(s):

• http://account.{BLOCKED}me.com/jp/addr.gif - inaccessible
• http://tech.{BLOCKED}net.com/jp/addr.gif- inaccessible

It does not have any downloading capability.

Information Theft

This backdoor steals the following information:

• Computer Name
• System Default Language ID
• OS Version
• Is administrator
• Is 64-bit

NOTES:

It posts the information to the following C&C servers:

• http://tech.{BLOCKED}net.com/jp/ahewt.asp
• http://tech.{BLOCKED}net.com/jp/cjbcs.asp
• http://tech.{BLOCKED}net.com/jp/dwqzj.asp
• http://tech.{BLOCKED}net.com/jp/ewiuj.asp
• http://tech.{BLOCKED}net.com/jp/fhery.asp
• http://tech.{BLOCKED}net.com/jp/kwlge.asp
• http://tech.{BLOCKED}net.com/j /qdlbo.asp
• http://tech.{BLOCKED}net.com/jp/rfhgj.asp
• http://tech.{BLOCKED}net.com/jp/sjhvx.asp
• http://tech.{BLOCKED}net.com/jp/uyiwe.asp
• http://tech.{BLOCKED}net.com/jp/vueyy.asp
• http://tech.{BLOCKED}net.com/jp/wukdf.asp
• http://tech.{BLOCKED}net.com/jp/xhtty.asp
• http://tech.{BLOCKED}net.com/jp/zhnxc.asp

It does not have rootkit capabilities.

It does not exploit any vulnerability.