RANSOM_GRYPHON.AUSG

September 13, 2017
 Analysis by: Oliver Ramirez
 ALIASES:

Ransom.BTCware (NORTON); Ransom:Win32/Betisrypt!rfn (Microsoft); Gen:Variant.Ransom.BTCWare.34 (BITDEFENDER)

 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 drops files as ransom note.

  TECHNICAL DETAILS

File Size:

116,224 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

27 Aug 2017

Payload:

Displays message/message boxes, 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • NUCLEAR

Ransomware Routine

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

  • .nuclear
  • nuclear

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

  • $recycle.bin
  • msocache
  • ProgramData
  • programdata
  • programdata\
  • windows
  • nvidia
  • intel
  • appdata
  • inetpub
  • temp
  • program files
  • programfiles (x86)
  • HELP.hta
  • BOOTMGR

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

  • [qeteway@{BLOCKED}ta.com].nuclear

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

  • %Application Data%\HELP.hta

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on 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.)

NOTES:

When %Application Data%\HELP.hta is opened, the following window will be shown:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.632.02

FIRST VSAPI PATTERN DATE:

01 Sep 2017

VSAPI OPR PATTERN File:

13.633.00

VSAPI OPR PATTERN Date:

02 Sep 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

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

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

Search and delete these files

[ 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.  
  • %Application Data%\HELP.hta

Step 5

Restore encrypted files from backup.


Did this description help? Tell us how we did.