Analysis by: Roland Marco Dela Paz

ALIASES:

Symantec : W32.SillyDC; Sophos : Mal/Palevo-A

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Copies itself in all available physical drives

This worm 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.

  TECHNICAL DETAILS

File Size: 150,016 bytes
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 05 Jan 2011

Installation

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

  • %Application Data%\qmkin.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 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 = %Application Data%\qmkin.exe

Propagation

This worm creates the following folders in all removable drives:

  • [DRIVE]:\DIJAMANTE

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

  • [DRIVE]:\DIJAMANTE\veciti.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]
{garbage codes}
shell\open\command=DIJAMANTE\\veciti.exe
{garbage codes}
Shell\open\command=DIJAMANTE\\veciti.exe
shellexecute=DIJAMANTE\\veciti.exe
{garbage codes}
open=DIJAMANTE\veciti.exe
{garbage codes}
shell\explore\command=DIJAMANTE\\veciti.exe
{garbage codes}
action=Open folder to view files using Windows Explorer
{garbage codes}
USEAUTOPLAY=1
{garbage codes}
{garbage codes}
{garbage codes}
icon=SHELL32.dll,4
{garbage codes}

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.

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.749.00
VSAPI OPR PATTERN Date: 05 Jan 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

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 = %Application Data%\qmkin.exe

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.  [DRIVE]:\DIJAMANTE

Step 5

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

[ Learn More ]
[autorun]
{garbage codes}
shell\open\command=DIJAMANTE\\veciti.exe
{garbage codes}
Shell\open\command=DIJAMANTE\\veciti.exe
shellexecute=DIJAMANTE\\veciti.exe
{garbage codes}
open=DIJAMANTE\veciti.exe
{garbage codes}
shell\explore\command=DIJAMANTE\\veciti.exe
{garbage codes}
action=Open folder to view files using Windows Explorer
{garbage codes}
USEAUTOPLAY=1
{garbage codes}
{garbage codes}
{garbage codes}
icon=SHELL32.dll,4
{garbage codes}

Step 6

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