Analysis by: Arianne Grace Dela Cruz
ALIASES:

UDS:Trojan.Win32.Agent2.a (KASPERSKY); W32/KillDisk.NCV!tr (FORTINET)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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: 117,000 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 23 Feb 2022
Payload: Wipes data

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 drops the following files:

  • %System%\drivers\{Random}.sys -> EaseUs partition driver used to aid disk wipe, deleted after loading

(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 modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\CrashControl
CrashDumpEnabled = 0

HKEY_USERS\{USER ID}\Software\
Microsoft\Windows\CurrentVersion\
Explorer\Advanced
ShowCompColor = 0

HKEY_USERS\{User ID}\Software\
Microsoft\Windows\CurrentVersion\
Explorer\Advanced
ShowInfoTip = 0

Other Details

This Trojan adds and runs the following services:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services
{Dropped driver name} = %System%\drivers\{Random}.sys

It does the following:

  • It disables the following service:
    • vss
  • It wipes data from the following:
    • PhysicalDrives{0-100}
    • Logical Drives
  • It reboots the system after execution.
  • It deletes the created service after starting.

It accepts the following parameters:

  • {Wait Time} -> sleep time of the malware before execution, value is 20 by default
  • {Restart Time} -> sleep time of the malware before restart, value is 35 by default

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.402.08
FIRST VSAPI PATTERN DATE: 23 Feb 2022
VSAPI OPR PATTERN File: 17.403.00
VSAPI OPR PATTERN Date: 24 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

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

Identify and terminate files detected as Trojan.Win32.KILLDISK.YECBW

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

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\Control\CrashControl
    • CrashDumpEnabled = 0
    • CrashDumpEnabled = {Default}
  • In HKEY_USERS\{USER ID}\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowCompColor = 0
    • ShowCompColor = {Default}
  • In HKEY_USERS\{User ID}\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowInfoTip = 0
    • ShowInfoTip = {Default}

Step 5

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.KILLDISK.YECBW. 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:

NOTES:
Restore the system from backup or reinstall the operating system (OS). Depending on the extent of the damage, and if the wiping of the MBR is unsuccessful, the system can be made bootable by doing a system repair using a Windows installer disk. If the Windows installer can still make the system boot up, recovery of the files will be futile as portions of the files were already corrupted.


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