TROJ_PAKES.ONA

 Analysis by: Sabrina Sioting

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes itself after execution.

It adds registry entries to enable its automatic execution at every system startup.

  TECHNICAL DETAILS

File Size:

106,496 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

No

Initial Samples Received Date:

30 Apr 2011

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

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

  • %User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It deletes itself after execution.

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
mssend = "%User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe"

Other System Modifications

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe = "%User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe:*:Enabled:ldrsoft "

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.128.03

FIRST VSAPI PATTERN DATE:

30 Apr 2011

Step 1

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

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • mssend = "%User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe = "%User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2\svcnost.exe:*:Enabled:ldrsoft"

Step 3

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. %User Profile%\Application Data\xi1ww1bqcwk2zpyfkec2ipi3bufxmxmj2

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_PAKES.ONA 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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