Analysis by: Mohammed Malubay
ALIASES:

Ransom:Win32/HwruGo.SV!MTB(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: Downloaded from the Internet, Dropped by other malware

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 connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Type: EXE
Memory Resident: No
Initial Samples Received Date: 28 Nov 2020
Payload: Displays graphics/image, Collects system information, Encrypts files, Connects to URLs/IPs

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.

Information Theft

This Ransomware gathers the following data:

  • Local IP Address
  • Host name
  • UID
  • Password of {BLOCKED}.{BLOCKED}.17.82:443

Other Details

This Ransomware connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.17.82:443

It does the following:

  • It attempts to encrypt but fails, because there are no keys included on configuration.
  • It displays the following error logs of files and folders that it attempted but failed to encrypt:

Ransomware Routine

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

  • __read_me_.txt

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

  • windows

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

  • .howareyou

It leaves text files that serve as ransom notes containing the following text:

  • %Desktop%\__read_me_.txt
  • %Public%\Desktop\__read_me_.txt
  • %System Root%\Users\Default\Desktop\__read_me_.txt

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.418.01
FIRST VSAPI PATTERN DATE: 16 Dec 2020
VSAPI OPR PATTERN File: 16.419.00
VSAPI OPR PATTERN Date: 17 Dec 2020

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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%\__read_me_.txt
  • %Public%\Desktop\__read_me_.txt
  • %System Root%\Users\Default\Desktop\__read_me_.txt

Step 4

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.HWRU.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 5

Restore encrypted files from backup.


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