Analysis by: Michael Cabel
ALIASES:

Kaspersky: Trojan.Win32.Agent.eimu;Microsoft: VirTool:Win32/CeeInject.gen!DG

 PLATFORM:

Windows 2000, Windows XP, Windows 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.

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.

  TECHNICAL DETAILS

File Size: 111,616 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 16 Dec 2010
Payload: Drops files

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:

  • %System Root%\RECYCLER\{Random SID}\Setupin.exe

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

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\{Random SID}\Setupin.exe"

Propagation

This worm 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]
open=winsys/winavg.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files using Windows Explorer
sHell\\open\command=winsys/winavg.exe
sHell\explore\\command=winsys/winavg.exe
useautoplay=1

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

  • MSN Messenger

NOTES:

Other Details

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

Proliferates through the following P2P applications:

  • BearShare
  • iMesh
  • Shareaza
  • Kazaa
  • DC++
  • eMule
  • LimeWire

  SOLUTION

Minimum Scan Engine: 8.900

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

Restart in Safe Mode

[ Learn More ]

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

Step 4

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

[ Learn More ]
[autorun]
open=winsys/winavg.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files using Windows Explorer
sHell\\open\command=winsys/winavg.exe
sHell\explore\\command=winsys/winavg.exe
useautoplay=1

Step 5

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