Analysis by: Ryan Paolo Maglaque
ALIASES:

Mal/Ktzware-A(Sophos);a variant of MSIL/Filecoder.Kuntzware.A trojan(Eset-NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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 encrypts files with specific file extensions.

  TECHNICAL DETAILS

File Size: 29,184 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 20 Jun 2017
Payload: 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.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .kuntzware
  • .doc
  • .docx
  • .log
  • .msg
  • .odt
  • .pages
  • .rtf
  • .tex
  • .txt
  • .wpd
  • .csv
  • .dat
  • .key
  • .keychain
  • .pps
  • .ppt
  • .pptx
  • .sdf
  • .tar
  • .tax2016
  • .vcf
  • .xml
  • .aif
  • .iff
  • .m3u
  • .m4a
  • .mid
  • .mp3
  • .mpa
  • .wav
  • .wma
  • .3g2
  • .3gp
  • .asf
  • .avi
  • .flv
  • .m4v
  • .mov
  • .mp4
  • .mpg
  • .rm
  • .srt
  • .swf
  • .vob
  • .wmv
  • .3dm
  • .3ds
  • .max
  • .obj
  • .bmp
  • .dds
  • .gif
  • .jpg
  • .png
  • .psd
  • .pspimage
  • .tga
  • .thm
  • .tif
  • .tiff
  • .yuv
  • .al
  • .eps
  • .ps
  • .svg
  • .xlr
  • .xls
  • .xlsx
  • .accdb
  • .db
  • .dbf
  • .mdb
  • .pdb
  • .sql
  • .7z
  • .cbr
  • .deb
  • .gz
  • .pkg
  • .rar
  • .rpm
  • .sitx
  • .tar.gz
  • .zip
  • .zipx
  • .wallet
  • .pdf

It avoids encrypting files found in the following folders:

  • windows
  • program files

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

  • .kuntzware

NOTES:
Due to code error, the malware does not encrypt files. It also seems that the malware is currently under development.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.482.07
FIRST VSAPI PATTERN DATE: 20 Jun 2017
VSAPI OPR PATTERN File: 13.483.00
VSAPI OPR PATTERN Date: 21 Jun 2017

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 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 RANSOM_KTZWARE.A. 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 this Knowledge Base page for more information.


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