Analysis by: Maria Emreen Viray
ALIASES:

Trojan:Win32/Tiggre!rfn (MICROSOFT)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 1,427,456 bytes
File Type: Other
Memory Resident: No
Initial Samples Received Date: 19 Aug 2021

Arrival Details

This Trojan 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 Trojan adds the following folders:

  • %Program Files%\6AkGp
  • %Program Files%\6AkGp\6AkGp

(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 drops the following files:

  • %Windows%\setupact32.log → if OS is 32 bit
  • %Windows%\setupact64.log → if OS is 64 bit
  • %Windows%\dbcode21mk.log

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

It adds the following processes:

  • "%System%\netsh.exe" interface ipv6 install
  • "%System%\netsh.exe" ipsec static add policy name=qianye
  • "%System%\netsh.exe" ipsec static add filterlist name=Filter1
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=445 protocol=TCP
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=135 protocol=TCP
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=139 protocol=TCP
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=445 protocol=UDP
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=135 protocol=UDP
  • "%System%\netsh.exe" ipsec static add filter filterlist=Filter1 srcaddr=any dstaddr=Me dstport=139 protocol=UDP
  • "%System%\netsh.exe" ipsec static add filteraction name=FilteraAtion1 action=block
  • "%System%\netsh.exe" ipsec static add rule name=Rule1 policy=qianye filterlist=Filter1 filteraction=FilteraAtion1
  • "%System%\netsh.exe" ipsec static set policy name=qianye assign=y

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

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\SoundResearch
UpdaterLastTimeChecked1 = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Installer\
Folders
%Program Files%\6AkGp\ = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Installer\
Folders
%Program Files%\6AkGp\6AkGp\ = 1

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Session Manager
PendingFileRenameOperations = \??\%Windows%\AppPatch\Acpsens.dll, , \??\%Windows%\system32\sens.dll, \??\%Windows%\AppPatch\Acpsens.dll, \??\%Windows%\system32\sens.dll, , \??\%Windows%\setupact32.log, \??\%Windows%\system32\sens.dll

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Session Manager
AllowProtectedRenames = 1

Other Details

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\SoundResearch

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.918.05
FIRST VSAPI PATTERN DATE: 21 Aug 2021
VSAPI OPR PATTERN File: 16.919.00
VSAPI OPR PATTERN Date: 22 Aug 2021

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

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

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\SOFTWARE\SoundResearch
    • UpdaterLastTimeChecked1 = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Folders
    • %Program Files%\6AkGp\ = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\Folders
    • %Program Files%\6AkGp\6AkGp\ = 1
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager
    • PendingFileRenameOperations = \??\%Windows%\AppPatch\Acpsens.dll, , \??\%Windows%\system32\sens.dll, \??\%Windows%\AppPatch\Acpsens.dll, \??\%Windows%\system32\sens.dll, , \??\%Windows%\setupact32.log, \??\%Windows%\system32\sens.dll
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Session Manager
    • AllowProtectedRenames = 1

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\SOFTWARE\SoundResearch

Step 5

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%\setupact32.log or %Windows%\setupact64.log
  • %Windows%\dbcode21mk.log

Step 6

Search and delete this folder

[ 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.
  • %Program Files%\6AkGp
  • %Program Files%\6AkGp\6AkGp

Step 7

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.FUPORPLEX.ENH. 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 the following Trend Micro Support pages for more information:


Did this description help? Tell us how we did.