Analysis by: Jay Garcia
ALIASES:

Win32/Farfli.CJT trojan(NOD32); VirTool:Win32/CeeInject.TD!bit(MICROSOFT)

 PLATFORM:

Windows

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

  • 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 does not have any propagation routine.

However, as of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 113,664 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 May 2019
Payload: Connects to URLs/IPs, Drops files, Terminates processes, Displays message/message boxes

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:

  • %Program Files%\java.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • %system%\cmd.exe /c del {malware path and file name} > nul
  • %Program Files%\java.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Autostart Technique

This Backdoor 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\Java(TM) Platform Sa 8.02
DisplayName = "Oracle Corporation"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
ImagePath = "%Program Files%\java.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Java(TM) Platform Sa 8.02
Start = "SERVICE_AUTO_START"

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\Java(TM) Platform Sa 8.02

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Java(TM) Platform Sa 8.02\MarkTime

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Java(TM) Platform Sa 8.02\Description

Other System Modifications

This Backdoor adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Java(TM) Platform Sa 8.02
MarkTime = "{date of execution}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Java(TM) Platform Sa 8.02
Description = "Java(TM) Platform SE 8 Oracle Corporation"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\W32Time
Type = "16"

(Note: The default value data of the said registry entry is 20.)

Propagation

This Backdoor does not have any propagation routine.

Backdoor Routine

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

  • {BLOCKED}.{BLOCKED}.110.250:7722

However, as of this writing, the said sites are inaccessible.

Rootkit Capabilities

This Backdoor does not have rootkit capabilities.

Process Termination

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

  • 360sd.exe
  • 360tray.exe
  • 360安全卫士
  • 360杀毒
  • ad-watch.exe
  • Ad-watch反间谍
  • ashDisp.exe
  • Avast网络安全
  • avcenter.exe
  • AVG
  • avgwdsvc.exe
  • avp.exe
  • AYAgent.aye
  • baiduSafeTray.exe
  • BaiduSd.exe
  • BitDefender
  • cfp.exe
  • Comodo杀毒
  • DR.WEB
  • egui.exe
  • F-Secure
  • f-secure.exe
  • K7TSecurity.exe
  • K7杀毒
  • knsdtray.exe
  • KSafeTray.exe
  • KvMonXP.exe
  • kxetray.exe
  • Mcshield.exe
  • mssecess.exe
  • NOD32
  • Outpostacs.exe
  • PSafe
  • PSafe反病毒
  • QQPCRTP.exe
  • QQ电脑管家
  • QUHLPSVC.EXE
  • QuickHeal
  • RavMonD.exe
  • remupd.exe
  • rtvscan.exe
  • SPIDer.exe
  • SysTray.exe
  • TMBMSRV.exe
  • UnThreat
  • UnThreat.exe
  • V3Svc.exe
  • vsserv.exe
  • 卡巴
  • 可牛
  • 安博士V3
  • 小红伞
  • 微软MSE
  • 江民
  • 熊猫卫士
  • 瑞星
  • 百度卫士
  • 百度杀毒
  • 诺顿
  • 趋势
  • 金山安全卫士
  • 金山毒霸
  • 韩国胶囊
  • 麦咖啡

Information Theft

This Backdoor does not have any information-stealing capability.

Other Details

This Backdoor does the following:

  • This backdoor has the following capabilities:
    • Change position of windows
    • Create services
    • Display message box
    • Download files
    • Execute files
    • Generate beep sound
    • Log keystrokes
    • Modify registry values
    • Open/Close CD drive
    • Swap Mouse Buttons
    • Turn On/Off Monitor
    • Wipe Master Boot Record Data

It deletes itself after execution.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.140.05
FIRST VSAPI PATTERN DATE: 29 May 2019
VSAPI OPR PATTERN File: 15.141.00
VSAPI OPR PATTERN Date: 30 May 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Restore your system's Master Boot Record (MBR)

To restore your system's Master Boot Record (MBR):

• On Windows 2000, XP, and Server 2003:

  1. Insert your Windows Installation CD into your CD drive then restart your computer.
  2. When prompted, press any key to boot from the CD.
  3. On the Main Menu, type r to enter the Recovery Console.
    (Note for Windows 2000: After pressing r, type c to choose the Recovery Console on the repair options screen.)
  4. Type the number that corresponds to the drive and folder that contains Windows (usually C:\WINDOWS) and press Enter.
  5. Type your Administrator password and press Enter.
  6. In the input box, type the following then press Enter:
    fixmbr {affected drive}
  7. Type exit and press Enter to restart the system normally.

• On Windows Vista, 7, and Server 2008:

  1. Insert your Windows Installation DVD into the DVD drive, then press the restart button on your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to choose the installation language. On the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Repair your computer.
  4. Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
  5. If the Startup Repair window appears, click Cancel, Yes, then Finish.
  6. In the System Recovery Options menu, click Command Prompt.
  7. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  8. Type exit and press Enter to close the Command Prompt window.
  9. Click Restart to restart your computer normally.

• On Windows 8, 8.1, and Server 2012:

  1. Insert your Windows Installation DVD in the DVD drive, then restart your computer.
  2. When prompted, press any key to boot from the DVD.
  3. Depending on your Windows Installation DVD, you might be required to select the keyboard layout. Then on the Windows Setup window, choose your language, locale, and input method. Click Next, then click Repair your computer.
  4. Click Troubleshoot>Advanced Options>Command Prompt.
  5. In the Command Prompt window, type the following then press Enter:
    BootRec.exe /fixmbr
  6. Type exit and press Enter to close the Command Prompt window.
  7. Click Continue to restart the system normally.

Step 3

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 4

Restart in Safe Mode

[ Learn More ]

Step 5

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
    • Java(TM) Platform Sa 8.02
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Java(TM) Platform Sa 8.02
    • MarkTime
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Java(TM) Platform Sa 8.02
    • Description

Step 6

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\SYSTEM\ControlSet001\services\Java(TM) Platform Sa 8.02
    • MarkTime = {date of execution}
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Java(TM) Platform Sa 8.02
    • Description = Java(TM) Platform SE 8 Oracle Corporation

Step 7

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time
    • From: Type = 16
      To: Type = 20

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.ZEGOST.AMY. 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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