Analysis by: Joshua Paul Ignacio


Trojan-Ransom.Conti (IKARUS); W32/Filecoder.C42A!tr.ransom (FORTINET)




  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes


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

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.


File Size: 189,440 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 01 Oct 2020
Payload: Drops files, Terminates processes, Encrypts files

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.


This Ransomware drops the following files:

  • {Malware Path}\{Filename from -log argument}.txt → If -log argument is used

It adds the following processes:

  • cmd.exe /c %System%\wbem\WMIC.exe shadowcopy where "ID={Shadowcopy ID}" delete → It will repeat this process depending on the number of shadow copies.

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

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • lslaif8aisuuugnzxbvmdjk

Other Details

This Ransomware does the following:

  • Accepts the following arguments:
    • -h {txtfile containing list of hosts to encrypt}
    • -p {txtfile containing list of folders} - Will encrypt first the folders in the list before proceeding to the others
    • -m {all|local|net|backups}
      • all - combination of net and local
      • local - delete backups and encrypt only locally found drives
      • net - delete backupds and encrypt only network shares
      • backups - delete backups
    • -log {Filename} - Outputs log on {Malware Path}\{Filename}.txt
    • -prockiller enabled - Terminate process not found in the following list:
      • spoolsv.exe
      • explorer.exe
      • sihost.exe
      • fontdrvhost.exe
      • cmd.exe
      • dwm.exe
      • LogonUI.exe
      • SearchUI.exe
      • lsass.exe
      • csrss.exe
      • smss.exe
      • winlogon.exe
      • services.exe
      • conhost.exe
      • svchost.exe
      • lsm.exe
      • wininit.exe
      • system
      • taskhost.exe
      • audiodg.exe
      • SearchIndexer.exe
      • sppsvc.exe
      • msdtc.exe
      • MSTASK.EXE
      • {Current Process}
    • -pids {process ids} - Contains list of pids (separated by comma) to be exempted from prockiller
  • When encrypting network shares it will check if the IP address starts with the following to ensure that it is encrypting local, non-Internet, systems:
    • 172.
    • 192.168.
    • 10.
    • 169.

Ransomware Routine

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

  • .dll
  • .exe
  • .lnk
  • .msi
  • .sys
  • .KZDBB
  • R3ADM3.txt
  • {Filename from -log argument}.txt

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

  • $Recycle.Bin
  • System Volume Information
  • Boot
  • Windows
  • temp
  • tmp
  • winnt
  • thumb
  • Trend Micro

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

  • .KZDBB

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

  • {Encrypted Directory}\R3ADM3.txt


Minimum Scan Engine: 9.800
VSAPI OPR PATTERN File: 16.333.04
VSAPI OPR PATTERN Date: 06 Nov 2020

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.XXPE50FFF038

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

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.  
  • {Malware Path}\{Filename from -log argument}.txt
  • {Encrypted Directory}\R3ADM3.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.CONTI.J. 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 6

Restore encrypted files from backup.

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