RANSOM_RDW.A

August 11, 2017
 Analysis by: Ryan Paolo Maglaque
 ALIASES:

Trojan-Ransom.MSIL.Agent.zp(Kaspersky);

 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:

57,856 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

25 Jul 2017

Payload:

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.

Installation

This Ransomware drops the following files:

  • {Malware directory}\dotnetaes.dll

Other Details

This Ransomware does the following:

  • Displays the following window as warning of the ransomware:

  • Displays the following window after encryption:

  • Requires the password SUPER_SECRET_KEY to decrypt files
  • Change the ownership of the directory C:\Users

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .mp4
  • .bmp
  • .zip
  • .rar
  • .7z
  • .tar
  • .gz
  • .json
  • .conf
  • .ico
  • .3ds
  • .aep
  • .mid
  • .ai
  • .aep
  • .c4d
  • .apk
  • .ini
  • .stl
  • .blend
  • .iso
  • .mp3
  • .html
  • .jar
  • .wav
  • .ipa
  • .swf
  • .m4a
  • .torrent
  • .js
  • .gif
  • .svg
  • .flv
  • .rtf
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .png
  • .csv
  • .sql
  • .mdb
  • .sln
  • .cs
  • .csv
  • .db
  • .mdf
  • .mdb
  • .ora
  • .php
  • .asp
  • .aspx
  • .html
  • .xml
  • .psd

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

  • .RDWF

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.556.08

FIRST VSAPI PATTERN DATE:

26 Jul 2017

VSAPI OPR PATTERN File:

13.557.00

VSAPI OPR PATTERN Date:

27 Jul 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

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 directory}\dotnetaes.dll

Step 3

Scan your computer with your Trend Micro product to delete files detected as RANSOM_RDW.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.

Step 4

Restore encrypted files from backup.


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