Analysis by: Jed Valderama
 Modified by: Mark Joseph Manahan

ALIASES:

Backdoor:Win32/Qakbot.M (Microsoft), PWS-Zbot.gen.ada (McAfee), W32.Qakbot (Symantec)

 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: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware, Via removable drives, Via Network Shares, Via peer-to-peer shares

This backdoor arrives via peer-to-peer (P2P) shares. It arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

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: 282,760 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Jun 2012
Payload: Terminates processes, Steals information, Connects to URLs/IPs

Arrival Details

This backdoor arrives via peer-to-peer (P2P) shares.

It arrives via removable drives.

It may arrive via network shares.

It 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:

  • %User Profile%\Application Data\Microsoft\{random}\{random}.exe

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

It drops the following non-malicious file:

  • %User Profile%\Application Data\Microsoft\{random}\{random}.dll

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

It creates the following folders:

  • %User Profile%\Application Data\Microsoft\{random}

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

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

  • {malware name}a
  • nekxhv

It injects itself into the following processes as part of its memory residency routine:

  • explorer.exe
  • iexplore.exe

Backdoor Routine

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

  • {BLOCKED}ysgtap.co.in
  • {BLOCKED}istr.in
  • {BLOCKED}vtkn.in.ua
  • {BLOCKED}son.in
  • {BLOCKED}uytdk.info
  • {BLOCKED}mentis.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:

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

It sends the information it gathers to remote sites.

Other Details

This backdoor connects to the following URL(s) to check for an Internet connection:

  • http://www.ip-adress.com/

It 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:

  • data
  • dnsname
  • domain
  • ext_ip
  • host
  • hostname
  • install_time
  • is_admin
  • lb
  • login
  • nick
  • os
  • pass
  • qbot_version
  • time
  • url
  • 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: 9.222.05
FIRST VSAPI PATTERN DATE: 27 Jun 2012
VSAPI OPR PATTERN File: 9.223.00
VSAPI OPR PATTERN Date: 28 Jun 2012

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_QAKBOT.DZ

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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. %User Profile%\Application Data\Microsoft\{random}

Step 5

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