Analysis by: rolandde

ALIASES:

P2P-Worm.Win32.Palevo.bpio (Kaspersky); Worm:Win32/Rimecud.DH (Microsoft)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

This worm arrives via 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 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 a website to send and receive information.

  TECHNICAL DETAILS

File Size: 328,199 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 03 Dec 2010
Payload: Launches DoS/DDoS attacks, Connects to URLs/IPs, Steals information

Arrival Details

This worm arrives via removable drives.

It may arrive via network shares.

Installation

This worm drops the following non-malicious files:

  • %System Root%\RECYCLER\{SID}\Desktop.ini
  • {Removable drive}:\vircure\Desktop.ini

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

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

  • %System Root%\RECYCLER\{SID}\MsMxEng.exe

(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}\MsMxEng.exe"

Propagation

This worm creates the following folders in all removable drives:

  • vircure

It drops copies of itself into the following folders used in peer-to-peer (P2P) networks:

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

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

  • {Removable drive}:\vircure\vircure32.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 codes}
[autorun
;{garbage codes}
open=vircure/vircure32.exe
;{garbage codes}
icon=%SystemRoot%\system32\SHELL32.dll,4
;{garbage codes}
action=Open folder to view files using Windows Explorer
;{garbage codes}
USEAUToplay=1
;{garbage codes}
shell\open\\command=vircure/vircure32.exe
;{garbage codes}
shell\\explore\command=vircure/vircure32.exe
;{garbage codes}

Backdoor Routine

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

  • Perform DoS attack
  • Download and execute files from a remote site
  • Propagate itself via shared folders and P2P networks
  • Propagate itself via MSN Messenger
  • Perform port scans
  • Open a remote desktop connection
  • Terminate itself

It connects to the following websites to send and receive information:

  • {BLOCKED}petition.com
  • {BLOCKED}eslounge.com
  • {BLOCKED}lmind.cn

As of this writing, the said sites are inaccessible.

NOTES:

Information Theft

This worm gathers the following information on the affected computer:

  • Mozilla Firefox account information
  • Protected Storage credentials
  • Internet Explorer AutoComplete passwords

Other Details

It may also arrive via MSN Messenger.

It does not continue with its malicious routine if it finds that its file name is C:\file.exe or if the logged user name is "CurrentUser"

The dropped AUTORUN.INF file is detected as TROJ_OTORUN.SMX.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 7.674.01
FIRST VSAPI PATTERN DATE: 03 Dec 2010
VSAPI OPR PATTERN File: 8.463.00
VSAPI OPR PATTERN Date: 30 Sep 2011

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

Remove malware files dropped/downloaded by WORM_PALEVO.EQAZ

Step 3

Identify and delete files detected as WORM_PALEVO.EQAZ using either the Startup Disk or Recovery Console

[ Learn More ]

Step 4

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\RECYCLER\{SID}
  • {Removable drive}:\vircure

Step 5

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 NT\CurrentVersion\Winlogon
    • Taskman = "%System Root%\RECYCLER\{SID}\MsMxEng.exe"

Step 6

Search and delete AUTORUN.INF files created by WORM_PALEVO.EQAZ that contain these strings

[ Learn More ]


;{garbage codes}
[autorun
;{garbage codes}
open=vircure/vircure32.exe
;{garbage codes}
icon=%SystemRoot%\system32\SHELL32.dll,4
;{garbage codes}
action=Open folder to view files using Windows Explorer
;{garbage codes}
USEAUToplay=1
;{garbage codes}
shell\open\command=vircure/vircure32.exe
;{garbage codes}
shell\explore\command=vircure/vircure32.exe
;{garbage codes}

Step 7

Scan your computer with your Trend Micro product to delete files detected as WORM_PALEVO.EQAZ. 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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