WORM_BUZUS.DES

This worm arrives by connecting affected removable drives to a system. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It executes commands from a remote malicious user, effectively compromising the affected system.

Arrival Details

This worm arrives by connecting affected removable drives to a system.

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:

• %User Profile%\Application Data\afd.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Cftmon32 = "%User Profile%\Application Data\afd.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Terminal Server\
Install\Software\Microsoft\
Windows\CurrentVersion\Run
Cftmon32 = "%User Profile%\Application Data\afd.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Terminal Server

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\napagent\LocalConfig\
Enroll

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\napagent\LocalConfig\
UI

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Program Groups
48211218 = "48211218"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and filename} = "{malware path and filename}:*:Enabled:Cftmon32"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP\Netsh\
Napmontr
BitNames = " NAP_TRACE_BASE NAP_TRACE_NETSH"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP\Netsh\
Napmontr
Guid = "710adbf0-ce88-40b4-a50d-231ada6593f0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP\Netsh
ControlFlags = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP\Netsh
Active = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Tracing\
Microsoft\NAP\Netsh
LogSessionName = "{hex values}"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

• {Drive Letter}:\Folder\SubFolder\file.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

;{garbage}
[autorun
;{garbage}
open=Folder\SubFolder\file.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files using Windows Explorer
shell\\open\command=Folder\SubFolder\file.exe
shell\\explore\command=Folder\SubFolder\file.exe
useautoplay=1

It sends messages that contain links to sites hosting remote copies of itself using the following instant-messaging (IM) applications:

• AIM
• MSN

Backdoor Routine

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

• Connect to a specified website
• Create processes
• Download files
• Gather information about the affected computer(Disk drive serial number, System drive details, Operating system, Processor architecture)
• Infect Drives
• Inject itself to WinRAR
• Open IM applications
• Send copies of itself through IM applications
• Update itself
• Disable firewall

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

• {BLOCKED}e.{BLOCKED}t.com