WORM_PALEVO.ASC

This worm arrives via peer-to-peer (P2P) shares. It arrives via removable drives. 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 copies of itself in all removable drives. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system. It runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk.

It connects to certain websites to send and receive information.

Arrival Details

This worm arrives via peer-to-peer (P2P) shares.

It arrives via removable drives.

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 Root%\RECYCLER\{SID}\svchost.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It drops the following non-malicious file:

• %System Root%\RECYCLER\{SID}\Desktop.ini

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

• %System Root%\RECYCLER\{SID}

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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

• explorer.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%System Root%\RECYCLER\{SID}\svchost.exe"

Propagation

This worm creates the following folders in all removable drives:

• nvda

It drops copies of itself in all removable drives.

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]
shellexecute="nvda\nvda.exe"
UseAutoPlay=1

Backdoor Routine

This worm opens a random port to allow a remote user to connect to the affected system. Once a successful connection is established, the remote user executes commands on the affected system.

It executes the following command(s) from a remote malicious user:

• download files or updates of itself
• launch SYN flood
• propagate via MSN messenger by sending messages containing a link where a copy of itself may be downloaded
• propagate itself via peer-to-peer networks

Other Details

This worm connects to the following website to send and receive information:

• mail.{BLOCKED}espace.org
• {BLOCKED}mania.biz
• {BLOCKED}mailer-list.com

NOTES:

It may also arrive as a downloaded file from links sent via messages in MSN messenger.

It may also arrive via the following P2P networks:

• Ares
• BearShare
• DC++
• eMule
• iMesh
• Kazaa
• Limewire
• Shareaza