RANSOM_OGRE.A

August 18, 2017
 Analysis by: Rheniel Rhay Ramos
 ALIASES:

Trojan-Ransom.Win32.Fairy.a (Kaspersky); Generic.Ransom.Ogre.FCECE66A (Bitdefender); Trojan:Win32/Skeeyah.A!bit (Microsoft)

 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 found in specific folders.

  TECHNICAL DETAILS

File Size:

394,240 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Jun 2017

Payload:

Terminates processes, Connects to URLs/IPs, 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.

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
OgreRSMWRE = “{Malware Path and File Name}”

Process Termination

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

  • taskmgr
  • explorer
  • iexplore
  • MicrosoftEdge
  • Steam
  • SteamService
  • steamwebhelper
  • msconfig
  • quickassist
  • seccenter
  • bdagent
  • vsserv
  • vsservp
  • ProductAgentService

Other Details

This Ransomware does the following:

  • It connects to the following URL(s) to download its encryption key:
    • http://ogrersmwre.{BLOCKED}b.com/enckey1
  • It connects to the following URL when the (Programme Test) hyperlink is clicked:
    • https://www.{BLOCKED}se.com/
  • It has an uncalled function that can decrypt the files it encrypts.

  • It opens a window which displays the ransom note:

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • A:\
  • B:\
  • C:\
  • D:\
  • E:\
  • F:\
  • G:\
  • H:\
  • I:\
  • J:\
  • K:\
  • L:\
  • M:\
  • N:\
  • O:\
  • P:\
  • Q:\
  • R:\
  • S:\
  • T:\
  • U:\
  • V:\
  • W:\
  • X:\
  • Y:\
  • Z:\
  • C:\Program Files (x86)\Steam\
  • C:\Program Files (x86)\Steam\steamapps\common\
  • C:\Windows\
  • C:\Windows\System32\

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

  • .ogre

NOTES:

The program has certain errors that prevents a few capabilities of the malware.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.454.01

FIRST VSAPI PATTERN DATE:

05 Jun 2017

VSAPI OPR PATTERN File:

13.455.00

VSAPI OPR PATTERN Date:

06 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

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

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • OgreRSMWRE = “{Malware Path and File Name}”

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_OGRE.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 6

Restore encrypted files from backup.


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