BKDR_QBOT.BC

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.

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

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

Process Termination

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

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

• ay.wellsfargo.com
• express.53.com
• ctm.53.com
• itreasury.regions.com
• itreasurypr.regions.com
• cpw-achweb.bankofamerica.com
• businessaccess.citibank.citigroup.com
• businessonline.huntington.com
• /cmserver/
• goldleafach.com
• iachwellsprod.wellsfargo.com
• achbatchlisting
• /achupload
• commercial2.wachovia.com
• commercial3.wachovia.com
• commercial4.wachovia.com
• wc.wachovia.com
• commercial.wachovia.com
• wcp.wachovia.com
• chsec.wellsfargo.com
• wellsoffice.wellsfargo.com
• /ibws/
• /stbcorp/
• /payments/ach
• trz.tranzact.org
• /wiret
• /payments/ach
• cbs.firstcitizensonline.com
• /corpach/
• scotiaconnect.scotiabank.com
• webexpress.tdbank.com
• businessonline.tdbank.com
• /wcmpw/
• /wcmpr/
• /wcmtr/
• tcfexpressbusiness.com
• trz.tranzact.org

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:

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

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:

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

This backdoor gathers passwords by monitoring the following applications:

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