WORM_ANIG.DUKKS

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

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

Arrival Details

This worm may arrive via network shares.

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

• %System%\{Malware File Name}.EXE

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

This worm 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\dfcsvc
Type = "110"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvcx
ErrorControl = "0"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
ImagePath = "{Malware File Name}.EXE /dfcsvc"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
DisplayName = "Distributed File Controller"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
DependOnService = "RpcSS"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
DependOnGroup = "0x0000"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\dfcsvc
ObjectName = "LocalSystem"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Osa32 = "{Malware File Name}.EXE"

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
GinaDll = "ntgina.dll"

(Note: The default value data of the said registry entry is MSGINA.DLL.)

Other System Modifications

This worm adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Ram32Data = ""

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Ram32ID = ""

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Ram32Group = ""

It creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{Malware Path and File Name} = "{Malware Path and File Name}:*:Enabled:{Malware File Name}"

Propagation

This worm searches the network for the following shared networks onto which it attempts to drop copies of itself:

• ADMIN$\System32\NTOSA32.EXE
• ADMIN$\System32\NTGINA.DLL

Backdoor Routine

This worm opens the following port(s) where it listens for remote commands:

• TCP 5190

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

• {BLOCKED}.{BLOCKED}.130.5

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

Dropping Routine

This worm drops the following file(s), which it uses for its keylogging routine:

• %System%\NTGINA.DLL - also detected as WORM_ANIG.DUKKS

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Stolen Information

This worm saves the stolen information in the following file:

• %System%\NTKBH32.DLL

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

NOTES:

It remotely creates this registry entry to ensure that the dropped .EXE file is executed at every system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
Osa32 = "NTOSA32.exe"

It also creates this registry entry to ensure that the dropped .DLL file is executed at every system startup:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
GinaDll = "ntgina.dll"