RANSOM_WINBAM.A

 Analysis by: John Donnie Celestre

 ALIASES:

N/A

 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:

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. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

280739 bytes

File Type:

ZIP

Memory Resident:

No

Initial Samples Received Date:

19 Jun 2017

Payload:

Connects to URLs/IPs, 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:

  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp\install.log <- installation log
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp\afterreboot.cfg
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp\setup.exe <- copy of itself
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp\DotNetFX461\NDP461-KB3102438-Web.exe <- installs .NET Framework
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\manifests\winb...exe_{16 random chars}_0001.0000_none_{16 random chars}.cdf-ms
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\manifests\winb...exe_{16 random chars}_0001.0000_none_{16 random chars}.manifest
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\manifests\winb..tion_{16 random chars}_0001.0000_none_{16 random chars}.cdf-ms
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\manifests\winb..tion_{16 random chars}_0001.0000_none_{16 random chars}.manifest
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb...exe_{16 random chars}_0001.0000_none_{16 random chars}\WinBamboozle.exe.config
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.cdf-ms
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.exe
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.exe.cdf-ms
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.exe.config
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.exe.manifest
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\WinBamboozle.manifest
  • %AppDataLocal%\Temp\ASPNETSetup_00000.log
  • %AppDataLocal%\Temp\dd_NDP461-KB3102438-Web_decompression_log.txt
  • %AppDataLocal%\Temp\dd_SetupUtility.txt
  • %AppDataLocal%\Temp\dd_TMPC356.tmp_decompression_log.txt
  • %AppDataLocal%\Temp\dd_wcf_CA_smci_20180612_001709_686.txt
  • %AppDataLocal%\Temp\Deployment\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}.application
  • %AppDataLocal%\Temp\Deployment\{8 random chars}.{3 random chars}\WinBamboozle.exe.manifest

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

  • %AppDataLocal%\Temp\Deployment
  • %AppDataLocal%\Temp\Deployment\{8 random chars}.{3 random chars}
  • %AppDataLocal%\Apps
  • %AppDataLocal%\Apps\2.0
  • %AppDataLocal%\Apps\2.0\Data
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\manifests
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb...exe_{16 random chars}_0001.0000_none_{16 random chars}
  • %AppDataLocal%\Apps\2.0\Data\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\Data
  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp\DotNetFX461

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

Download Routine

This Ransomware accesses the following websites to download files:

  • http://download.microsoft.com/download/3/5/9/35980F81-60F4-4DE3-88FC-8F962B97253B/NDP461-KB3102438-Web.exe <- non-malicious file, it is executed to ensure that the malware runs in the proper .NET Framework

Other Details

This Ransomware connects to the following URL(s) to check for an Internet connection:

  • http://go.microsoft.com/

It does the following:

  • This malware is a ZIP file containing the following files:
    • {malware extraction path}\full\Application Files
    • {malware extraction path}\full\Application Files\WinBamboozle_1_0_0_0
    • {malware extraction path}\full\Application Files\WinBamboozle_1_0_0_0\WinBamboozle.application
    • {malware extraction path}\full\Application Files\WinBamboozle_1_0_0_0\WinBamboozle.exe.config.deploy
    • {malware extraction path}\full\Application Files\WinBamboozle_1_0_0_0\WinBamboozle.exe.deploy
    • {malware extraction path}\full\Application Files\WinBamboozle_1_0_0_0\WinBamboozle.exe.manifest
    • {malware extraction path}\full\Test
    • {malware extraction path}\full\Test\data.txt
    • {malware extraction path}\full\setup.exe
    • {malware extraction path}\full\WinBambozzle.application
  • It requires reboot after installation
  • The malware is still in development and only encrypt files found in %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\Test displaying a command prompt during encryption

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\Test

(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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 appends the following extension to the file name of the encrypted files:

  • .{5 random chars}

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

  • %AppDataLocal%\Apps\2.0\{8 random chars}.{3 random chars}\{8 random chars}.{3 random chars}\winb..tion_{16 random chars}_0001.0000_{16 random chars}\Test\_README.txt

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.482.08

FIRST VSAPI PATTERN DATE:

20 Jun 2017

VSAPI OPR PATTERN File:

13.483.00

VSAPI OPR PATTERN Date:

21 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

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • {malware extraction path}\full
  • %AppDataLocal%\Temp\VSD{4 random chars}.tmp
  • %AppDataLocal%\Temp\Deployment
  • %AppDataLocal%\Apps

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.
  • %AppDataLocal%\Temp\ASPNETSetup_00000.log
  • %AppDataLocal%\Temp\dd_NDP461-KB3102438-Web_decompression_log.txt
  • %AppDataLocal%\Temp\dd_SetupUtility.txt
  • %AppDataLocal%\Temp\dd_TMPC356.tmp_decompression_log.txt
  • %AppDataLocal%\Temp\dd_wcf_CA_smci_20180612_001709_686.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as RANSOM_WINBAM.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 the following Trend Micro Support pages for more information:

Step 6

Restore encrypted files from backup.


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