Analysis by: Raymart Christian Yambot

ALIASES:

Gen:Variant.Zusy.515850 (BITDEFENDER)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

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

It drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size: 4,188,160 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 18 Dec 2023
Payload: Drops files, Disables AV, Encrypts files, Modifies system registry, Terminates processes

Arrival Details

This Ransomware 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 Ransomware adds the following folders:

  • %Temp%\QLOG

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

It drops the following files:

  • %Temp%\QLOG\ThreadId(Number).LOG

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

It adds the following processes:

  • """{Malware file path}"" --password {String} --escalated --parent-sid ""S-1-5-21-2019512041-42308"
  • "cmd" /C fsutil behavior set SymlinkEvaluation R2R:1
  • "cmd" /C fsutil behavior set SymlinkEvaluation R2L:1
  • "cmd" /C net use
  • "cmd" /C wmic service where name='vss' call ChangeStartMode Manual
  • "cmd" /C net start vss
  • "cmd" /C vssadmin.exe delete shadows /all /quiet
  • "cmd" /C net stop vss
  • "cmd" /C wmic service where name='vss' call ChangeStartMode Disabled
  • "powershell" $logs = Get-WinEvent -ListLog * | Where-Object {$_.RecordCount} | Select-Object -ExpandProperty LogName ; ForEach ( $l in $logs | Sort | Get-Unique ) {[System.Diagnostics.Eventing.Reader.EventLogSession]::GlobalSession.ClearLog($l)}

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLinkedConnections = 1

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\LanmanServer\Parameters
MaxMpxCt = 65535

Process Termination

This Ransomware terminates the following services if found on the affected system:

  • (.*?)sql(.*?).
  • acronisagent
  • acrsch2svc
  • backup
  • backupexecagentaccelerator
  • backupexecagentbrowser
  • backupexecdivecimediaservice
  • backupexecjobengine
  • backupexecmanagementservice
  • backupexecrpcservice
  • backupexecvssprovider
  • gxblr
  • gxcimgr
  • gxclmgrs
  • gxcvd
  • gxfwd
  • gxmmm
  • gxvss
  • gxvsshwprov
  • memtas
  • mepocs
  • msexchange
  • msexchange
  • msexchange\$
  • mvarmor
  • mvarmor64
  • pdvfsservice
  • qbcfmonitorservice
  • qbdbmgrn
  • qbidpservice
  • sap
  • sap\$
  • sapd\$
  • saphostcontrol
  • saphostexec
  • sapservice
  • sophos
  • sql
  • veeam
  • veeamdeploymentservice
  • veeamnfssvc
  • veeamtransportsvc
  • vmms
  • vsnapvss
  • vss
  • wsbexchange

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

  • agntsvc
  • avagent
  • avscc
  • bedbh
  • benetns
  • bengien
  • beserver
  • cagservice
  • cvd
  • cvfwd
  • cvmountd
  • cvods
  • dbeng50
  • dbsnmp
  • dellsystemdetect
  • encsvc
  • enterpriseclient
  • excel
  • firefox
  • infopath
  • isqlplussvc
  • msaccess
  • mspub
  • mvdesktopservice
  • mydesktopqos
  • mydesktopservice
  • notepad
  • ocautoupds
  • ocomm
  • ocssd
  • onenote
  • oracle
  • outlook
  • powerpnt
  • pvlsvr
  • qbcfmonitorservice
  • qbdbmgrn
  • qbidpservice
  • raw_agent_svc
  • sap
  • saphostexec
  • saposcol
  • sapstartsrv
  • sqbcoreservice
  • sql
  • steam
  • synctime
  • tbirdconfig
  • teamviewer
  • teamviewer_service
  • thebat
  • thunderbird
  • tv_w32
  • tv_x64
  • veeamdeploymentsvc
  • veeamnfssvc
  • veeamtransportsvc
  • visio
  • vmcompute
  • vmms
  • vmwp
  • vsnapvss
  • vxmon
  • winword
  • wordpad
  • xfssvccon

Other Details

This Ransomware does the following:

  • It terminates itself if it detects that the sample is being executed within a virtual environment.
  • It requires the correct input password to proceed in its intended routine.
  • Checks for the presence of the following processes:
    • wininit.exe
    • winlogon.exe
    • lsass.exe

It accepts the following parameters:

  • --password {String} → Password to enter landing.
  • --paths {Directory} → Defines the path that parses directories; if this flag is used and left empty, all directories will be scanned.
  • --ips {IP Addresses} → Allows for providiing IP addresses.
  • --exclude {Directory} → Excluded directories for encryption.
  • --timer → Sets a time delay before execution.
  • --safe → Restart in safe mode.
  • --escalated → Execute the sample with admin privelege.
  • --parent-sid → Sets the Security Identifier
  • --no-domain → Disable encyption of domain area.
  • --no-network → Disable ecnryption of network area.
  • --no-ef → Disable extension filter.
  • --no-ff → Disable file filter.
  • --no-df → Disable directory filter.
  • --no-proc → Processes will not be terminated protocol driver not attached.
  • --no-service → Services will not be stopped.
  • --debugspread
  • --kill-cluster
  • --impersonate
  • --force
  • --print-image
  • --print-delay
  • --spreads
  • --spread-vcenter
  • --spread-process
  • --no-local
  • --no-extension
  • --no-wallpaper
  • --no-delete
  • --no-destruct
  • --no-zero
  • --no-escalate

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file name:

  • #recycle
  • #recycle
  • autorun.inf
  • autorun.inf
  • autorun.ini
  • boot.ini
  • boot.ini
  • bootfont.bin
  • bootfont.bin
  • bootmgfw.efi
  • bootmgfw.efi
  • bootmgr
  • bootmgr
  • bootmgr.efi
  • bootmgr.efi
  • bootsect.bak
  • bootsect.bak
  • desktop.ini
  • desktop.ini
  • iconcache.db
  • iconcache.db
  • ntldr
  • ntldr
  • ntuser.dat
  • ntuser.dat
  • ntuser.dat.log
  • ntuser.dat.log
  • ntuser.ini
  • ntuser.ini
  • thumbs.db
  • thumbs.db

It avoids encrypting files with the following strings in their file path:

  • $recycle.bin
  • $windows.~bt
  • $windows.~ws
  • admin$
  • admin$
  • appdata
  • appdata
  • application data
  • boot
  • boot
  • config.msi
  • google
  • intel
  • ipc$
  • mozilla
  • msocache
  • netlogon
  • perflogs
  • programdata
  • system volume information
  • sysvol
  • tor browser
  • windows
  • windows
  • windows.old
  • windows.old

It appends the following extension to the file name of the encrypted files:

  • {Original filename}.{Original Extension}.VayvEy6cPo.1

It drops the following file(s) as ransom note:

  • {All Available Directories}\README-RECOVER-VayvEy6cPo.txt

It avoids encrypting files with the following file extensions:

  • 386
  • adv
  • ani
  • bat
  • bin
  • cmd
  • com
  • cpl
  • cur
  • deskthemepack
  • diagcab
  • diagcfg
  • diapkg
  • dll
  • drv
  • exe
  • hlp
  • hta
  • icl
  • icns
  • ico
  • ics
  • idx
  • key
  • lnk
  • lock
  • mod
  • mpa
  • msc
  • msi
  • msp
  • msstyles
  • msu
  • nls
  • nomedia
  • ocx
  • pdb
  • prf
  • ps1
  • rom
  • rtp
  • scr
  • shs
  • spl
  • sys
  • theme
  • themepack
  • VayvEy6cPo
  • wpx

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.902.03
FIRST VSAPI PATTERN DATE: 26 Dec 2023
VSAPI OPR PATTERN File: 18.903.00
VSAPI OPR PATTERN Date: 27 Dec 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

    • Troj.Win32.TRX.XXPE50FFF075

Step 2

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 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

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\Microsoft\Windows\CurrentVersion\Policies\System
    • EnableLinkedConnections  = 1
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\LanmanServer\Parameters
    • MaxMpxCt = 65535

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.  
  • %Temp%\QLOG\ThreadId(Number).LOG
  • {All Available Directories}\README-RECOVER-VayvEy6cPo.txt

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.
  • %Temp%\QLOG

Step 7

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.AGENDA.RY. 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:

Step 8

Restore encrypted files from backup.


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