Analysis by: Roland Marco Dela Paz
ALIASES:

Backdoor:Win32/Otlard.A (Microsoft)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This backdoor may be downloaded by other malware/grayware/spyware from remote sites.

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: 53,449 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Feb 2010
Payload: Compromises system security

Arrival Details

This backdoor may be downloaded by other malware/grayware/spyware from remote sites.

Installation

This backdoor adds the following mutexes to ensure that only one of its copies runs at any one time:

  • gootkit

It injects codes into the following process(es):

  • svchost.exe

Other System Modifications

This backdoor adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM
Randseed_1 = {hex values}

HKEY_LOCAL_MACHINE\SYSTEM
Randseed_2 = {hex values}

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Epoch
Epoch = 84

(Note: The default value data of the said registry entry is 82.)

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and filename} = {malware path and filename}:Enabled:{malware filename}

Backdoor Routine

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

  • Connect to a website
  • Download and execute file(s)
  • Insert iframe codes to websites

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

  • {BLOCKED}.{BLOCKED}.229.140
  • {BLOCKED}n.cc
  • {BLOCKED}0.org
  • {BLOCKED}8quoob8moh.com
  • {BLOCKED}us4nohshiy.com
  • {BLOCKED}eshacei2ae.com

NOTES:

It steals log in credentials that are related to the following FTP clients:

  • Bulletproof FTP
  • CoffeeCup FTP
  • CoreFTP
  • CuteFtp
  • FF FTP
  • FTP Commander
  • FTP Explorer
  • Far
  • Filezilla
  • Firefox
  • FlashFXP
  • Frigate
  • FtpRush
  • Internet Explorer
  • Opera
  • SecureFX
  • SmartFtp
  • Total Commander
  • UltraFXP
  • WSFTP
  • WinSCP

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 06.880.01
FIRST VSAPI PATTERN DATE: 27 Feb 2010

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

Scan your computer with your Trend Micro product and note files detected as BKDR_OTLARD.N

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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
    • Randseed_1 = {hex values}
  • In HKEY_LOCAL_MACHINE\SYSTEM
    • Randseed_2 = {hex values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware path and filename} = {malware path and filename}:Enabled:{malware filename}

Step 5

Restore this modified 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\Epoch
    • From: Epoch = 84
      To: Epoch = 82

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_OTLARD.N. 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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