Analysis by: JasperM
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Infects files

However, as of this writing, the said sites are inaccessible.

It appends its codes to target files.

  TECHNICAL DETAILS

File Size: Varies
File Type: PE
Memory Resident: Yes
Initial Samples Received Date: 05 Nov 2007
Payload: Connects to URLs/Ips

Arrival Details

However, as of this writing, the said sites are inaccessible.

Installation

This file infector injects codes into the following process(es):

  • WINLOGON.EXE

Other System Modifications

This file infector creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\\Winlogon.exe = "%System%\Winlogon.exe:*:enabled:@shell32.dll,-1"

File Infection

This file infector infects the following file types:

  • EXE
  • SCR

It appends its codes to target files.

Backdoor Routine

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

  • proxim.{BLOCKED}lpa.info

Other Details

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

  • It hooks the following APIs so that whenever the APIs are called, it performs its infection routine:
  • ZwCreateFile
  • ZwCreateProcess
  • ZwCreateProcessEx

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 4.815.00
VSAPI PATTERN Date: 06 Nov 2007
VSAPI PATTERN Date: 11/6/2007 12:00:00 AM

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

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\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %System%\Winlogon.exe = %System%\Winlogon.exe:*:enabled:@shell32.dll,-1

Step 3

Scan your computer with your Trend Micro product to clean files detected as PE_VIRUT.PAU. 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.

Step 4

Scan your computer with your Trend Micro product to delete files detected as PE_VIRUT.PAU. 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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