Analysis by: Jasen Sumalapao

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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 executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size: 450,048 bytes
Memory Resident: Yes
Initial Samples Received Date: 08 Jul 2012
Payload: Downloads files, Connects to URLs/IPs

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 component file(s):

  • %Application Data%\DCap.exe - detected as TROJ_JORK.NES
  • %System Root%\config\1.exe - detected as TROJ_JORK.NES
  • %System Root%\config\2.exe - detected as TSPY_BANKER.ZZQ
  • %Application Data%\{current date}.txt (in format mm.dd.yyyy)
  • %Application Data%\arquivo.txt
  • %Application Data%\new.txt
  • %Application Data%\SETUP19.txt

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

It creates the following folders:

  • %System Root%\config

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

It injects threads into the following normal process(es):

  • csrss.exe
  • lsass.exe
  • svchost.exe

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
DCap = "%Application Data%\DCap.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
%System Root%\config\1.exe = "%System Root%\config\1.exe"

Other System Modifications

This Trojan also creates the following registry entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
ConsentPromptBehaviorAdmin = "0"

Dropping Routine

This Trojan executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://www.{BLOCKED}u.com//piwik/libs/{random 1 character}.jpg - inaccessible
  • http://www.{BLOCKED}ulo.es/{random 1 character}.jpg - detected as TROJ_JORIK.NES
  • http://publicad.{BLOCKED}u.ac.th/php/libmysql.dll - non-malicious component
  • http://phdph.{BLOCKED}u.ac.th//L10Apps/6.inf - non-malicious component

It saves the files it downloads using the following names:

  • %Application Data%\libmysql.dll
  • %Application Data%\{random 1 character}.jpg

(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.)

Other Details

This Trojan connects to the following time servers to determine the current date:

  • http://realtime.services.disqus.com

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.245.00
FIRST VSAPI PATTERN DATE: 09 Jul 2012
VSAPI OPR PATTERN File: 9.245.00
VSAPI OPR PATTERN Date: 09 Jul 2012

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

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.
  • %System Root%\config

Step 4

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Application Data%\libmysql.dll
  • %Application Data%\{current date}.txt (in format mm.dd.yyyy)
  • %Application Data%\arquivo.txt
  • %Application Data%\new.txt
  • %Application Data%\SETUP19.txt
  • %Application Data%\DCap.exe
  • %Application Data%\{random 1 character}.jpg

Step 5

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
    • DCap = "%Application Data%\DCap.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • %System Root%\config\1.exe = "%System Root%\config\1.exe"

Step 6

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\CurrentVersion\policies\system
    • EnableLUA = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • ConsentPromptBehaviorAdmin = "0"

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_JORIK.NES. 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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