BKDR_FARFLI.FPAT

 Analysis by: Ryan Gardo

 ALIASES:

Win32/DH{gRKBE0GBEQNnJ4EQAjU}(AVG); Trojan.Agent.QQ(Malwarebytes); Backdoor.Win32.Inject (Ikarus)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes


  TECHNICAL DETAILS

File Size:

101,752 bytes

File Type:

, EXE

Memory Resident:

Yes

Initial Samples Received Date:

17 Feb 2015

Installation

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

  • %Windows%\WinAutoUpdate.com

Autostart Technique

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Bcdefg Ijklmnop Rst
DisplayName = "Bcdefg Ijklmnop Rstuvwxy Bcde"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Bcdefg Ijklmnop Rst
ImagePath = "%Windows%\WinAutoUpdate.com"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Bcdefg Ijklmnop Rst
Start = "2"

Other System Modifications

This backdoor adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\Group

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap
ProxyBypass = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap
IntranetName = "1"

(Note: The default value data of the said registry entry is 0.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
ZoneMap
UNCAsIntranet = "1"

(Note: The default value data of the said registry entry is 0.)

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.496.03

FIRST VSAPI PATTERN DATE:

17 Feb 2015

VSAPI OPR PATTERN File:

11.497.00

VSAPI OPR PATTERN Date:

18 Feb 2015

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM
    • Group
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services
    • Bcdefg Ijklmnop Rst

Step 5

Restore this modified 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\Internet Settings\ZoneMap
    • From: ProxyBypass = "1"
      To: ProxyBypass = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap
    • From: IntranetName = "1"
      To: IntranetName = "0"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap
    • From: UNCAsIntranet = "1"
      To: UNCAsIntranet = "0"

Step 6

Search and delete this file

[ 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%\WinAutoUpdate.com

Step 7

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