WORM_PALEVO.ARL

 Analysis by: Michael Cabel

 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This worm may be downloaded by other malware/grayware/spyware from remote sites. It may be unknowingly downloaded by a user while visiting malicious websites.

  TECHNICAL DETAILS

File Size:

81,056 bytes

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

21 Jul 2010

Arrival Details

This worm may be downloaded by other malware/grayware/spyware from remote sites.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

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

  • %Windows%\jusched.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

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
Java developer Script Browse = %Windows%\jusched.exe

Other System Modifications

This worm modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv
Start = 4

(Note: The default value data of the said registry entry is 2.)

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile\AuthorizedApplications\
List
%Program Files%\MSN Messenger\msnmsgr.exe = %Program Files%\MSN Messenger\msnmsgr.exe:*:Enabled:MSN Me ssenger 7.0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{Malware Path and File Name} = {Malware Path and File Name}:*:Enabled:1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Program Files%\MSN Messenger\msnmsgr.exe = %Program Files%\MSN Messenger\msnmsgr.exe:*:Enabled:MSN Messenger 7.0

Propagation

This worm sends copies of itself to target recipients using the following instant-messaging (IM) applications:

  • Yahoo! Messenger
  • MSN Messenger
  • Skype

Backdoor Routine

This worm connects to any of the following IRC server(s):

  • nuevo.{BLOCKED}ardigital.com
  • server1.{BLOCKED}ootmusic.com

Adware Routine

This worm connects to the following URLs to download and display ads:

  • http://browseusers.{BLOCKED}ce.com/Browse/Browse.aspx
  • http://x.{BLOCKED}cecdn.com
  • http://js.{BLOCKED}cecdn.com
  • http://c3.ac-images.{BLOCKED}cecdn.com
  • http://p.ic.{BLOCKED}t.com
  • http://{BLOCKED}.{BLOCKED}.36.96/index.php

Other Details

Based on analysis of the codes, it has the following capabilities:

  • This worm attempts to establish connection to the following remote host on port 80:
    • {BLOCKED}.{BLOCKED}.38.168
    • {BLOCKED}.{BLOCKED}.36.96
    • {BLOCKED}.{BLOCKED}.80.58
    • {BLOCKED}.{BLOCKED}.86.23
    • {BLOCKED}.{BLOCKED}.86.30
    • {BLOCKED}.{BLOCKED}.86.37
    • {BLOCKED}.{BLOCKED}.131.147
    • {BLOCKED}.{BLOCKED}.131.148
    • {BLOCKED}.{BLOCKED}.131.149
    • {BLOCKED}.{BLOCKED}.131.150
    • {BLOCKED}.{BLOCKED}.131.156
    • {BLOCKED}.{BLOCKED}.131.163
    • {BLOCKED}.{BLOCKED}.131.174
    • {BLOCKED}.{BLOCKED}.131.181
    • {BLOCKED}.{BLOCKED}.131.182
    • {BLOCKED}.{BLOCKED}.131.187
    • {BLOCKED}.{BLOCKED}.71.154
    • {BLOCKED}.{BLOCKED}.71.166
  • It tries to open port 2345 in an attempt to join any of the following IRC server:
    • server1.{BLOCKED}ootmusic.com
    • nuevo.{BLOCKED}ardigital.com
  • It uses the following credentials to join the IRC server:
    PASS xxx
    NICK NEW-[USA|00|P|83944] USER XP-5814 * 0 :{Computer Name}
  • Once a successful connection is established, it sends the following message that contains a link pointing to a copy of itself:
    #gf! :.m.s|.m.e is this you on pic?

  SOLUTION

Minimum Scan Engine:

8.900

VSAPI PATTERN File:

07.322.22

VSAPI PATTERN Date:

21 Jul 2010

VSAPI PATTERN Date:

7/21/2010 12:00:00 AM

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Terminate a process file/s detected as WORM_PALEVO.ARL

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

Step 3

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Java developer Script Browse = C:\WINDOWS\jusched.exe
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\AuthorizedApplications\List
    • %Program Files%\MSN Messenger\msnmsgr.exe = %Program Files%\MSN Messenger\msnmsgr.exe:*:Enabled:MSN Me ssenger 7.0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {Malware Path and File Name} = {Malware Path and File Name}:*:Enabled:1
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Program Files%\MSN Messenger\msnmsgr.exe = %Program Files%\MSN Messenger\msnmsgr.exe:*:Enabled:MSN Messenger 7.0

Step 4

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv
    • From: Start = 4
      To: 2

Step 5

Scan your computer with your Trend Micro product to delete files detected as WORM_PALEVO.ARL. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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