Analysis by: Jaime Benigno Reyes

ALIASES:

Backdoor.Win32.QBot.pez (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

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 then deletes itself afterward. It is injected into all running processes to remain memory resident.

It connects to a website to send and receive information.

It sends the information it gathers to remote sites.

It prevents users from visiting antivirus-related websites that contain specific strings.

  TECHNICAL DETAILS

File Size: 290,816 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 23 May 2013
Payload: Compromises system security

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 file(s)/component(s):

  • %Application Data%\MICROSOFT\{random1}\{random2}.dll

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It drops the following copies of itself into the affected system:

  • %Application Data%\MICROSOFT\{random1}\{random1}.exe
  • %Application Data%\{random number}.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %Application Data%\MICROSOFT\{random1}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It executes then deletes itself afterward.

It is injected into all running processes to remain memory resident.

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

  • {malware name}a
  • Global\{random}

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random3} = "%Application Data%\MICROSOFT\{random1}\{random1}.exe"

It modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ctfmon.exe = "%Application Data%\MICROSOFT\{random1}\{random1}.exe /c %System%\ctfmon.exe"

(Note: The default value data of the said registry entry is "%System%\ctfmon.exe".)

Backdoor Routine

This backdoor connects to the following websites to send and receive information:

  • {BLOCKED}tkrich.net
  • {BLOCKED}carusled.org
  • {BLOCKED}m.{BLOCKED}v.ua
  • {BLOCKED}mausj.org
  • {BLOCKED}nz.net
  • {BLOCKED}n.org
  • {BLOCKED}s.{BLOCKED}v.ua

Process Termination

This backdoor terminates the following processes if found running in the affected system's memory:

  • ctfmon.exe
  • dbgview.exe
  • mirc.exe
  • msdev.exe
  • ollydbg.exe

Information Theft

This backdoor monitors the Internet Explorer (IE) activities of the affected system, specifically the address bar or title bar. It recreates a legitimate website with a spoofed login page if a user visits banking sites with the following strings in the address bar or title bar:

  • .web-access.com
  • .webcashmgmt.com
  • /achupload
  • /cashman/
  • /cashplus/
  • /clkccm/
  • /cmserver/
  • /corpach/
  • /ibws/
  • /payments/ach
  • /stbcorp/
  • /wcmpr/
  • /wcmpw/
  • /wcmtr/
  • /wires/
  • /wiret
  • access.jpmorgan.com
  • accessonline.abnamro.com
  • achbatchlisting
  • ay.wellsfargo.com
  • bankeft.com
  • blilk.com
  • businessaccess.citibank.citigroup.com
  • businessbankingcenter.synovus.com
  • business-eb.ibanking-services.com
  • businessinternetbanking.synovus.com
  • businessonline.huntington.com
  • businessonline.tdbank.com
  • cashproonline.bankofamerica.com
  • cbs.firstcitizensonline.com
  • chsec.wellsfargo.com
  • cmol.bbt.com
  • commercial.bnc.ca
  • commercial.wachovia.com
  • commercial2.wachovia.com
  • commercial3.wachovia.com
  • commercial4.wachovia.com
  • corporatebanking
  • cpw-achweb.bankofamerica.com
  • ctm.53.com
  • directline4biz.com
  • directp
  • each.bremer.com
  • ebanking-services.com
  • e-facts.org
  • e-moneyger.com
  • express.53.com
  • firstmeritib.com
  • firstmeritib.com/defaultcorp.aspx
  • goldleafach.com
  • iachwellsprod.wellsfargo.com
  • ibc.klikbca.com
  • iris.sovereignbank.com
  • itreasury.regions.com
  • itreasurypr.regions.com
  • jsp/mainWeb.jsp
  • ktt.key.com
  • moneymanagergps.com
  • netconnect.bokf.com
  • nj00-wcm
  • ocm.suntrust.com
  • onlineserv/CM
  • otm.suntrust.com
  • paylinks.cunet.org
  • premierview.membersunited.org
  • providentnjolb.com
  • scotiaconnect.scotiabank.com
  • securentrycorp.amegybank.com
  • securentrycorp.zionsbank.com
  • singlepoint.usbank.com
  • svbconnect.com
  • tcfexpressbusiness.com
  • tmcb.zionsbank.com
  • tmconnectweb
  • treas-mgt.frostbank.com
  • treasury.pncbank.com
  • trz.tranzact.org
  • tssportal.jpmorgan.com
  • wc.wachovia.com
  • wcp.wachovia.com
  • web-cashplus.com
  • webexpress.tdbank.com
  • wellsoffice.wellsfargo.com

It sends the information it gathers to remote sites.

Other Details

This backdoor prevents users from visiting antivirus-related websites that contain the following strings:

  • .eset
  • agnitum
  • ahnlab
  • arcabit
  • avast
  • avg
  • avira
  • avp
  • bit9
  • bitdefender
  • castlecops
  • centralcommand
  • clamav
  • clearclouddns
  • comodo
  • computerassociates
  • cpsecure
  • defender
  • download.microsoft.
  • drweb
  • emsisoft
  • esafe
  • etrust
  • ewido
  • explabs.
  • fortinet
  • f-prot
  • f-secure
  • gdata
  • grisoft
  • hacksoft
  • hauri
  • hautesecure.com
  • ikarus
  • jotti
  • k7computing
  • kaspersky
  • malware
  • mcafee
  • networkassociates
  • nod32
  • norman
  • norton
  • panda
  • pctools
  • phishtank.com
  • prevx
  • quickheal
  • rising
  • rootkit
  • sanasecurity
  • securecomputing
  • sophos
  • spamhaus
  • spyware
  • sunbelt
  • symantec
  • threatexpert
  • threatfire
  • trendmicro
  • truste.com
  • update.microsoft.
  • virus
  • webroot.
  • wilderssecurity
  • windowsupdate

NOTES:

This backdoor is capable of connecting to a certain IRC server using a certain port and joins a channel where it receives commands from a malicious user.

It sends the following information to its C&C server:

  • dnsname
  • domain
  • ex_addr
  • ex_code
  • ex_module
  • ex_module_base
  • ext_ip
  • hostname
  • install_time
  • is_admin
  • nick
  • os
  • qbot_version
  • qbot_version
  • th_args
  • th_flags
  • th_title
  • time
  • user

This backdoor gathers passwords by monitoring the following applications:

  • firefox.exe
  • iexplore.exe
  • msmsgs.exe
  • msnmsgr.exe
  • opera.exe
  • outlook.exe
  • skype.exe
  • wscntfy.exe
  • wuauclt.exe
  • yahoomessenger.exe

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.936.06
FIRST VSAPI PATTERN DATE: 23 May 2013
VSAPI OPR PATTERN File: 9.937.00
VSAPI OPR PATTERN Date: 24 May 2013

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

Scan your computer with your Trend Micro product and note files detected as BKDR_QBOT.SM

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random3} = "%Application Data%\MICROSOFT\{random1}\{random1}.exe"

Step 5

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • From: ctfmon.exe = "%Application Data%\MICROSOFT\{random1}\{random1}.exe /c %System%\ctfmon.exe"
      To: ctfmon.exe = "%System%\ctfmon.exe"

Step 6

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.  
  • %Application Data%\MICROSOFT\{random1}

Step 7

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