Analysis by: John Donnie Celestre
ALIASES:

Trojan:Win32/Occamy.B (MICROSOFT), Trojan-Ransom.MikoYan (IKARUS)

 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: 473,088 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 13 Jul 2018
Payload: Terminates processes, Displays message/message boxes, Displays windows, 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.

Process Termination

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

  • "taskmgr"
  • "explorer"

Other Details

This Ransomware does the following:

  • Users are prompted with the following message boxes:

  • A fake windows update is shown while the encryption routine is happening in the background:
  • It displays the following as part of its ransom note:

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .3gp
  • .ahok
  • .apk
  • .asp
  • .aspx
  • .avi
  • .doc
  • .doc
  • .docx
  • .encrypt
  • .flac
  • .html
  • .jpeg
  • .jpg
  • .MOV
  • .mov
  • .mp3
  • .mp4
  • .php
  • .png
  • .ppt
  • .pptx
  • .psd
  • .rar
  • .raw
  • .txt
  • .wav
  • .wma
  • .wmv
  • .xls
  • .xlsx
  • .zip

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

  • "Bin"
  • "indows"
  • "tings"
  • "System Volume Information"
  • "cache"
  • "very"
  • "rogram Files (x86)"
  • "rogram Files"
  • "boot"
  • "efi"
  • ".old"

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

  • .jewsomware

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.376.02
FIRST VSAPI PATTERN DATE: 13 Jul 2018
VSAPI OPR PATTERN File: 14.377.00
VSAPI OPR PATTERN Date: 14 Jul 2018

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_SNEAKYJ.THGACAH. 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 3

Restore encrypted files from backup.


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