Analysis by: Michael Jhon Ofiaza
ALIASES:

Trojan-Ransom.Win32.Cryptor.bqr (Kaspersky) , Ransom:Win32/GandCrab.A (Microsoft) , Trojan Horse (Norton)

 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.

  TECHNICAL DETAILS

File Size: 486,400 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 08 Feb 2018
Payload: Terminates processes, 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 drops the following files:

  • %Application Data%\info.exe -> copy of itself
  • %Application Data%\recovery.txt -> ransom note
  • {encrypted folder}\How Recovery Files.txt -> ransom note

(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.)

It adds the following processes:

  • vssadmin.exe Delete Shadow /All /Quiet
  • cmd.exe /C bcdedit /set {default} recoveryenabled No
  • cmd.exe /C bcdedit /set {default} bootstatuspolicy ignoreallfailures
  • cmd.exe /c wbadmin DELETE SYSTEMSTATEBACKUP
  • cmd.exe /c wmic SHADOWCOPY DELETE

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • BleepingComputer_rapid

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
Encrypter_074 = %Application Data%\info.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
userinfo = %Application Data%\recovery.txt

Process Termination

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

  • agntsvc.exe
  • agntsvc.exe
  • ashDisp.exe
  • avengine.exe
  • avgnt.exe
  • AVP.EXE
  • cfp.exe
  • cmdagent.exe
  • dbeng50.exe
  • dbsnmp.exe
  • ekrn.exe
  • encsvc.exe
  • excel.exe
  • firefoxconfig.exe
  • fsguiexe.exe
  • infopath.exe
  • isqlplussvc.exe
  • Mcshield.exe
  • msaccess.exe
  • msftesql.exe
  • msmpeng.exe
  • mspub.exe
  • mydesktopqos.exe
  • mydesktopservice.exe
  • mysqld.exe
  • mysqld-nt.exe
  • mysqld-opt.exe
  • NortonAntiBot.exe
  • ocautoupds.exe
  • ocomm.exe
  • ocssd.exe
  • onenote.exe
  • oracle.exe
  • outlook.exe
  • pccpfw.exe
  • persfw.exe
  • powerpnt.exe
  • smc.exe
  • sqbcoreservice.exe
  • sqlagent.exe
  • sqlbrowser.exe
  • sqlservr.exe
  • sqlwriter.exe
  • steam.exe
  • synctime.exe
  • taskmgr.exe
  • tbirdconfig.exe
  • thebat.exe
  • thebat64.exe
  • thunderbird.exe
  • visio.exe
  • winword.exe
  • wordpad.exe
  • xfssvccon.exe

Other Details

This Ransomware adds the following scheduled tasks:

  • Task Name: Encrypter
    Schedule: Every minute
    Task to be run: %Application Data%\info.exe
  • Task Name: EncrypterSt
    Schedule: On Logon
    Task to be run: %Application Data%\info.exe

(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.)

Ransomware Routine

This Ransomware avoids encrypting files found in the following folders:

  • Windows
  • intel
  • nvidia
  • temp

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

  • .rapid

NOTES:

This ransomware displays the following image after execution:

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.962.02
FIRST VSAPI PATTERN DATE: 12 Feb 2018
VSAPI OPR PATTERN File: 13.963.00
VSAPI OPR PATTERN Date: 13 Feb 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

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

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
    • Encrypter_074 = %Application Data%\info.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • userinfo = %Application Data%\recovery.txt

Step 4

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.  
  • %Application Data%\info.exe -> copy of itself
  • %Application Data%\recovery.txt -> ransom note
  • {encrypted folder}\How Recovery Files.txt -> ransom note

Step 5

Deleting Scheduled Tasks

The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

  • Encrypter - %Application Data%\info.exe
  • EncrypterSt - %Application Data%\info.exe

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each {Task Name} values listed above in the Name column.
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the listed {Task to be run}.
  5. If the strings match the list above, delete the task.

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

  1. Open the Windows Task Scheduler. To do this:
    • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
    • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
  5. If the said string is found, delete the task.

Step 6

Scan your computer with your Trend Micro product to delete files detected as RANSOM_RAPID.THBABAH. 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 7

Restore encrypted files from backup.


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