Analysis by: Ryan Paolo Maglaque
 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

Canal de infección Dropped by other malware, Downloaded from the Internet

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

Tamaño del archivo 2,457,088 bytes
Tipo de archivo EXE
Residente en memoria No
Fecha de recepción de las muestras iniciales 06 Oct 2016
Carga útil Encrypts files

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:

  • %Desktop%\READ_TO_DECRYPT.html ← Ransom Note

(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This Trojan encrypts files with the following extensions:

  • .aes
  • .aif
  • .all
  • .and
  • .avi
  • .bak
  • .big
  • .bkp
  • .bmp
  • .cfg
  • .csv
  • .dbf
  • .dem
  • .doc
  • .eEp
  • .end
  • .eps
  • .flv
  • .gam
  • .gc
  • .gif
  • .ico
  • .iif
  • .inf
  • .ini
  • .int
  • .jpg
  • .m3u
  • .m4a
  • .m4v
  • .map
  • .max
  • .mdb
  • .mid
  • .mov
  • .mp3
  • .mp4
  • .mpa
  • .mpg
  • .msg
  • .nan
  • .nes
  • .nil
  • .obj
  • .odt
  • .off
  • .pc=
  • .pct
  • .pdb
  • .pdf
  • .png
  • .pps
  • .ppt
  • .prf
  • .psd
  • .ptr
  • .rom
  • .sav
  • .sql
  • .svg
  • .tif
  • .tmp
  • .txt
  • .vob
  • .wav
  • .wma
  • .wmv
  • .wpd
  • .wps
  • .xlr
  • .xls

It renames encrypted files using the following names:

  • {Random Values}.encrypted

It does the following:

  • Encrypts files in Desktop and its subdirectories

NOTES:

Ransomware fails to drop the ransom note and change the extensions of encrypted files in windows 7.

The content of the Ransom Note dropped in Desktop:

  SOLUTION

Motor de exploración mínimo 9.850
Primer archivo de patrones de VSAPI 12.822.08
Primera fecha de publicación de patrones de VSAPI 07 Oct 2016
Versión de patrones OPR de VSAPI 12.823.00
Fecha de publicación de patrones OPR de VSAPI 08 Oct 2016

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

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

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.
  • %Desktop%\READ_TO_DECRYPT.html

Step 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPTGO.SM. 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 5

Restore encrypted files from backup.


Did this description help? Tell us how we did.