BKDR_CYCBOT.CJ

October 09, 2012
 Analysis by: kathleenno
 Modified by: Kathleen Notario
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor 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 downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

186,368 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Jul 2011

Payload:

Downloads files, Terminates processes

Arrival Details

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

  • %Application Data%\Microsoft\conhost.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.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
conhost = "%Application Data%\Microsoft\conhost.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "explorer.exe, %Application Data%\dwm.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%User Temp%\csrss.exe"

(Note: The default value data of the said registry entry is {blank}.)

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\MIcrosoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = "http=127.0.0.1:{random}"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\0001\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Hardware Profiles\Current\Software\
Microsoft\windows\CurrentVersion\
Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_CONFIG\Software\Microsoft\
windows\CurrentVersion\Internet Settings
ProxyEnable = "1"

(Note: The default value data of the said registry entry is 0.)

Backdoor Routine

This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}ookdatabseonline.com
  • http://{BLOCKED}tekrck.com
  • http://{BLOCKED}nediconline.com
  • http://{BLOCKED}ckonline.com
  • http://{BLOCKED}tcatalogs.com
  • http://{BLOCKED}tteonlines.com
  • http://{BLOCKED}ilantispam.com

Process Termination

This backdoor terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • Alwil Software*
  • Avast*
  • AvastUI.exe
  • Avira*
  • McAfee*
  • Norton*
  • Symantec*
  • avast
  • avgnt.exe
  • avira
  • bitdef
  • ccsvchst.exe
  • drweb
  • kasper
  • mcafee
  • mcagent.exe
  • nod32
  • norton

Dropping Routine

This backdoor drops the following files wherein it saves the information it gathers:

  • %Application Data%\9EAE.6BA

(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.)

Download Routine

This backdoor saves the files it downloads using the following names:

  • %Application Data%\dwm.exe - also detected as BKDR_CYCBOT.CJ
  • %User Temp%\csrss.exe - also detected as BKDR_CYCBOT.CJ

(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.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}btech.com/images/133.jpg
  • http://{BLOCKED}btech.com/images/134.jpg
  • http://{BLOCKED}upport.com/images/livechat.png
  • http://{BLOCKED}upport.com/images/logo.png
  • http://{BLOCKED}ianchat.net/images/christian12.jpg
  • http://{BLOCKED}ianchat.net/images/christian13.jpg
  • http://{BLOCKED}ianchat.net/images/christian14.jpg
  • http://{BLOCKED}cscriptinstaller.com/pics/k5.jpg
  • http://{BLOCKED}cscriptinstaller.com/pics/l2.jpg
  • http://{BLOCKED}atnow.com/1.gif
  • http://{BLOCKED}atnow.com/2.gif
  • http://{BLOCKED}tentsonline.com/images/pdf.jpg
  • http://imgg.{BLOCKED}0.net/716/716354_m60.jpg
  • http://imgg.{BLOCKED}0.net/716/716354_m61.jpg
  • http://imgg.{BLOCKED}0.net/716/716354_m62.jpg
  • http://{BLOCKED}atagent.com/img/footer_intel.gif
  • http://{BLOCKED}atagent.com/img/footer_intel.jpg
  • http://{BLOCKED}atinc.com/wp-content/images/cpc.jpg
  • http://{BLOCKED}atinc.com/wp-content/images/cpc.png
  • http://{BLOCKED}boardpoint.com/images/template/h.cgi
  • http://{BLOCKED}boardpoint.com/images/template/header.jpg
  • http://{BLOCKED}laucoma.org/images/lhous3.gif
  • http://{BLOCKED}laucoma.org/images/lhous4.gif
  • http://{BLOCKED}et.com.my/thelab/images/wiley.jpg

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

8.280.11

FIRST VSAPI PATTERN DATE:

11 Jul 2011

VSAPI OPR PATTERN File:

8.281.00

VSAPI OPR PATTERN Date:

11 Jul 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

Identify and terminate files detected as BKDR_CYCBOT.CJ

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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\CurrentVersion\Run
    • conhost = "%Application Data%\Microsoft\conhost.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
    • Shell = "explorer.exe, %Application Data%\dwm.exe"
  • In HKEY_CURRENT_USER\Software\MIcrosoft\Windows\CurrentVersion\Internet Settings
    • ProxyServer = "http=127.0.0.1:{random}"

Step 4

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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • From: load = "%User Temp%\csrss.exe"
      To: load =
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = "1"
      To: ProxyEnable = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = "1"
      To: ProxyEnable = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\Current\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = "1"
      To: ProxyEnable = 0
  • In HKEY_CURRENT_CONFIG\Software\Microsoft\windows\CurrentVersion\Internet Settings
    • From: ProxyEnable = "1"
      To: ProxyEnable = 0

Step 5

Search and delete this file

[ 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%\9EAE.6BA

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_CYCBOT.CJ. 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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