RANSOM_BANACRYPT.THBBOAH

 Analysis by: Christian Noel Olalia

 ALIASES:

Trojan-Ransom.Win32.Agent.jbe (KASPERSKY); Trojan.Gen.2 (NORTON); Troj/Banaran-A (SOPHOS_LITE)

 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. It encrypts files found in specific folders.

  TECHNICAL DETAILS

File Size:

972,800 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

19 Feb 2018

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.

Other Details

This Ransomware displays the following message boxes:


It drops the following file(s)/component(s):

  • %User Temp%\Event_v.data

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 encrypts files with the following extensions:

  • .txt
  • .pdf
  • .doc
  • .docx
  • .xls
  • .ods
  • .zip
  • .log
  • .gif
  • .png
  • .log
  • .xlsx
  • .xls
  • .pptx
  • .msg
  • .jpeg
  • .jpg
  • .kdbx

It encrypts files found in the following folders:

  • %System Root%
  • %User Profile%

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It avoids encrypting files found in the following folders:

  • %Windows%
  • %Program Files%
  • %ProgramData%
  • %System Root%\Android
  • %System Root%\$RecycleBin
  • %System Root%\$RECYCLE.BIN
  • %System Root%\Windows.old
  • %System Root%\Java
  • %System Root%\MinGW
  • %System Root%\MongoDB
  • %System Root%\Python
  • %System Root%\Python27
  • %System Root%\Hacking

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

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

  • .bananaCrypt

NOTES:

This ransomware displays the following ransom note:

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.978.01

FIRST VSAPI PATTERN DATE:

19 Feb 2018

VSAPI OPR PATTERN File:

13.979.00

VSAPI OPR PATTERN Date:

20 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

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.  
  • %Desktop%\README.txt
  • %User Temp%\Event_v.data

Step 4

Scan your computer with your Trend Micro product to delete files detected as RANSOM_BANACRYPT.THBBOAH. 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 5

Restore encrypted files from backup.


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