WORM_ADDNEW.B

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.

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.

It performs denial of service (DoS) attacks on affected systems using specific flooding method(s).

Arrival Details

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.

Installation

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

• %Application Data%\Microsoft\svchost.exe

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

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

• HelloDDoser

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
svchost.exe = "%Application Data%\Microsoft\svchost.exe"

Propagation

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

• svchost.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:

[autorun]
shell=verb
open=svchost.exe
action=Open folder to view files
shell\open=Open
icon=%SystemRoot%\system32\SHELL32.dll,4

Backdoor Routine

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

• TCP port 3085

It executes the following commands from a remote malicious user:

• Download File
• Start/Stop Flooding
• Update itself
• Uninstall Itself
• Display message box
• Make itself idle
• Execute files
• Steal Mozilla Firefox passwords

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

• {BLOCKED}logdns.bounceme.net

As of this writing, the said servers are currently inaccessible.

Denial of Service (DoS) Attack

This worm performs denial of service (DoS) attacks on affected systems using the following flooding method(s):

• UDP Flood
• SYN Flood