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TROJ_ZCLICK.JK

November 11, 2014
 Analysis by: Rika Joi Gregorio
 ALIASES:

PWS:Win32/Zbot(Microsoft), MysticCompressor!D5799004292A(McAfee), W32/Zbot.CPPP!tr(Fortinet), a variant of Win32/Kryptik.CPPP trojan(Eset)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet


This spyware uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

  TECHNICAL DETAILS

File Size:

294,066 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Nov 2014

Payload:

Connects to URLs/IPs, Displays windows

Installation

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

  • %System%\{random file name 2}.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It drops the following copies of itself into the affected system and executes them:

  • %Application Data%\{random folder name}\{random file name 1}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It drops the following files:

  • %Windows%\Tasks\Security Center Update - {random digits}.job -> points to %Application Data%\{random folder name}\{random file name 1}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It uses the Windows Task Scheduler to add a scheduled task that executes the copies it drops.

It creates the following folders:

  • %Application Data%\{random folder name}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This spyware registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random digits}
ImagePath = ""%System%\{random file name 2}.exe" -service "%Application Data%\{random folder name}\{random file name 1}.exe""

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random digits}
DisplayName = "Security Center Server - {random digits}"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random folder name}\{random file name 1}.exe"

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random folder name}\{random file name 1}.exe"

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random digits}

The scheduled task executes the malware every:

  • every hour from 2 AM for 24 hours every day

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\PRQzDA

HKEY_CURRENT_USER\Software\{random key}

HKEY_LOCAL_MACHINE\Software\PRQzDA

HKEY_LOCAL_MACHINE\Software\{random key}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\PRQzDA
dynamicdata = "{hex value}"

HKEY_CURRENT_USER\Software\{random key}
License = "444"

HKEY_LOCAL_MACHINE\Software\PRQzDA
dynamicdata = "{hex value}"

HKEY_LOCAL_MACHINE\Software\{random key}
License = "444"

Download Routine

This spyware connects to the following URL(s) to download its configuration file:

  • http://{BLOCKED}.{BLOCKED}.167.122:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.238.9:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.167.184:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.145.146:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.241.19:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.103.45:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.147.168:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.18.188:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.117.34:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.170.117:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.139.138:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.202.175:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.229.208:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.104.218:443/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.194.102:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.216.149:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.224.48:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.102.172:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.114.196:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.65.96:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.64.145:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.134.56:1080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.134.57:1080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.238.163:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.227.149:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.40.105:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.241.49:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.243.66:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.72.174:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.197.150:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.49.116:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.49.118:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.48.27:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.94.46:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.111.148:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.243.76:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.194.229:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.16.171:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.137.56:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}.{BLOCKED}.137.59:8080/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}t.su/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}sctv.com/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}top.su/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}emech.com/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}emech.com:80/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}trola.com/b/{eve|opt|letr}/{hash}
  • http://{BLOCKED}egta.su//b/{eve|opt|letr}/{hash}

Information Theft

This spyware s configuration file contains the following information:

  • Search URL (referrer url)
  • Update URL (new C&C)
  • Click URL (redirection url source)
  • Mutex Name
  • Flash URL

NOTES:

This hooks the following APIs:

  • GetCursorInfo
  • GetCursorPos
  • GetMessageA
  • GetMessagePos
  • GetMessageW
  • MessageBoxA
  • MessageBoxExA
  • MessageBoxExW
  • MessageBoxIndirectA
  • MessageBoxIndirectW
  • MessageBoxW
  • PeekMessageA
  • PeekMessageW
  • PlaySoundA
  • PlaySoundW
  • RegCloseKey
  • RegCreateKeyA
  • RegCreateKeyExA
  • RegCreateKeyExW
  • RegCreateKeyW
  • RegEnumKeyExA
  • RegEnumKeyExW
  • RegEnumValueA
  • RegEnumValueW
  • RegOpenKeyA
  • RegOpenKeyExA
  • RegOpenKeyExW
  • RegOpenKeyW
  • RegQueryInfoKeyA
  • RegQueryInfoKeyW
  • RegQueryValueExA
  • RegQueryValueExW
  • SetCursorPos
  • WaveOutWrite

It may display a full screen window with loaded URLs. This window is focused when a hooked API is used. When the window is active, it performs various mouse movements and scrolling.

  SOLUTION

Minimum Scan Engine:

9.700

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ 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\SYSTEM\CurrentControlSet\Services
    • SecurityCenterServer{random digits}
  • In HKEY_CURRENT_USER\Software
    • PRQzDA
  • In HKEY_CURRENT_USER\Software
    • {random key}
  • In HKEY_LOCAL_MACHINE\Software
    • PRQzDA
  • In HKEY_LOCAL_MACHINE\Software
    • {random key}

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
    • {random} = "%Application Data%\{random folder name}\{random file name 1}.exe"
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • {random} = "%Application Data%\{random folder name}\{random file name 1}.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%\{random folder name}

Step 7

Search and delete these files

[ Learn More ]
There may be some 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.
  • %Windows%\Tasks\Security Center Update - {random digits}.job

Step 8

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

Step 9

Scan your computer with your Trend Micro product to delete files detected as TROJ_ZCLICK.JK. 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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